Glugea sp. infecting Sardinella aurita in Algeria

• Published in: Journal of parasitic diseases Vol. 46; no. 3; pp. 672 - 685
• Main Authors: Ramdani, Souhila, Ramdane, Zouhir, Slamovits, Claudio H., Trilles, Jean-Paul
• Format: Journal Article
• Language: English
• Published: New Delhi Springer India 2022; Springer Nature B.V
• Subjects: Connective tissues; Glugea; Health Promotion and Disease Prevention; Infectious Diseases; Medicine; Medicine & Public Health; Nucleotide sequence; Original; Original Article; Parasites; rRNA; Sardinella aurita; Seasonal variations; Spores; Transmission electron microscopy; Xenomas; Algeria; Histology; SSU rDNA; Algeria; Ultrastructure; Microsporidia
• ISSN: 0971-7196; 0975-0703
• DOI: 10.1007/s12639-022-01483-5

Parasitological examination of the commercially important pelagic fish Sardinella aurita Valenciennes, 1847 (Clupeidae) from the Eastern coast of Algeria revealed xenomas in the peritoneal cavity, suggesting a microsporidian infection. The prevalence of the disease was approximately 30% on average, higher in smaller individuals and showing significant seasonal variation. The xenomas contained numerous ellipsoidal spores, surrounded by a dense layer of connective tissue. Spore sizes were 6.10 ± 0.38 µm length and 3.54 ± 0.43 µm width. Ultrastructural examination by transmission electron microscopy showed various development stages of the parasite, including meronts, sporonts, sporoblasts and mature spores. The internal organization of the mature spores, with a single nucleus, prominent posterior vacuole, a lamellar polaroplast and an isofilar polar tube arranged in a single row, was typical of the genus Glugea . The DNA sequence of the small subunit ribosomal RNA gene confirmed that this parasite belongs to the genus Glugea. Genetic and morphologic comparison with G. sardinellensis , a species previously described in the same host from Tunisia shows many similarities, although some molecular and morphometric inconsistencies precluded the unambiguous assignment of our samples to G. sardinellensis . At the same time, we do not find sufficient grounds to erect a new taxon for our parasite. We discuss the implications of our findings for the current state of the systematics of Glugea .