Abstract
Heterosporis saurida is a microsporidian that infects lizardfish, Saurida undosquamis (Richardson, 1848), in the Arabian Sea. Spores were isolated from infected lizardfish and used to infect derived fish cell lines: common carp brain (CCB), epithelioma papulosum cyprinid (EPC), fathead minnow epithelial (FHM), rainbow trout gonad (RTG), bluegill fry (BF‐2) and chinook salmon embryo (CHSE). Non‐fish cell lines were also tested that include: insect (SF‐9), rabbit (RK‐13) and African green monkey (Vero E6). No growth of H. saurida was observed in any fish cell line, SF‐9 or Vero E6 cell lines. H. saurida spores grew only in RK‐13 cell line and were detected by immunofluorescence. Developmental stages of H. saurida were seen in RK‐13 cells by light and transmission electron microscopy, and species identification was confirmed by sequencing. This study demonstrated that H. saurida was able to proliferate in the mammalian RK‐13 cell line, which thus represents an in vitro model for conducting molecular genetics and cell–pathogen interaction studies of Heterosporis.