Humoral immune responses of the grouper Epinephelus akaara against the microsporidium Glugea epinephelusis

Abstract

The humoral immune responses of grouper Epinephelus akaara to a natural infection with Glugea epinephelusis was studied by ELISA utilizing intact mature spores as the coated antigen. Results showed that a specific humoral immune response was elicited, but the intensity of infection (in terms of the number of cysts) was not related to the antibody level in naturally infected hosts. The differences in the antigenicity of intact mature spores and soluble spore proteins derived from cracked mature spores were also analyzed. Results suggested that similar antigen epitopes existed between the 2 groups. Additionally, antigen component patterns and the distribution of antigen with immunogenicity were investigated by using the western blot and the immunofluorescent antibody technique (IFAT). The new parasitic microsporidium has specific polypeptide patterns comparable to the reported fish microsporidians. The main antigenic substances are concentrated on the surface of spores, and are mostly located on the anterior and posterior end of the spore bodies. Most surface components of the G. epinephelusis spores are soluble. The potential role of the surface components in initiating infection was also discussed. KEY WORDS: Glugea epinephelusis · Microsporidia · Epinephelus akaara · Humoral immune responses · antigenicityResale or republication not permitted without written consent of the publisher

Phylogeny and morphology of Glugea hertwigi from rainbow smelt Osmerus mordax found in Prince Edward Island, Canada

“…Wu et al (2005) assigned the same sequence (AY090038) to the poorly described species G. epinephelus from the Hong Kong grouper E. akaara. Subsequently, taxonomic and molecular characterization of G. epinephelusis was mentioned by Zhang et al (2005) in a study of immune response of E. akaara against this microsporidium, but no molecular data were given.…”

Outbreak of enteric microsporidiosis of hatchery‐bred juvenile groupers, Epinephelus spp., associated with a new intranuclear microporidian in China

“…This is the first report of an intranuclear microsporidian species infecting cultured groupers and the second occurrence of microsporidiosis in groupers in China (Zhang et al . ).…”

“…Among parasitic agents, Cryptocaryon irritans , Trypanosoma epinepheli , Glugea epinephelusis and Petalosoma epinephelis were found to be responsible for sporadic mortality of cultured groupers (Zhang et al . ; Li et al . ; Luo et al .…”

Ultrastructural and molecular characterization of Glugea serranus n. sp., a microsporidian infecting the blacktail comber, Serranus atricauda (Teleostei: Serranidae), in the Madeira Archipelago (Portugal)

“…Presently, there are 33 Glugea species, predominantly reported adhering to organs of the digestive tract of freshwater and marine fishes (Lom 2002;Vagelli et al 2005;Wu et al 2005;Voronin and Iukhimenko 2010;Su et al 2014;AbdelBaki et al 2015a, b;Azevedo et al 2016). To our best knowledge, and despite fish microsporidia lacking clear host specificity (Lom and Dyková 1992;Lom et al 1995;Nagasawa and Cruz-Lacierda 2004;Payghan et al 2009), the parasite here described constitutes the first occurrence of a Glugea species infecting a marine fish of the family Serranidae in the Madeira Archipelago, and one of the few reports of microsporidians infecting serranids worldwide (Zhang et al 2004(Zhang et al , 2005Wu et al 2005;Marzouk et al 2010;Jithendran et al 2011).…”