Effect of oral administration ofKudoa septempunctatagenotype ST3 in adult BALB/c mice

Abstract

Kudoa septempunctata (Myxozoa: Multivalvulida) infects the muscles of olive flounder (Paralichthys olivaceus, Paralichthyidae) in the form of spores. To investigate the effect of K. septempunctata spores in mammals, adult BALB/c mice were fed with spores of K. septempunctata genotype ST3 (1.35 × 105 to 1.35 × 108 spores/mouse). After ingestion of spores, the mice remained clinically normal during the 24-h observation period. No spores were found in any tissue examined by histopathological screening. Quantitative PCR screening of the K. septempunctata 18S rDNA gene revealed that the K. septempunctata spores were detected only in the stool samples from the spore-fed groups. Collectively, these findings suggest that K. septempunctata spores are excreted in faeces and do not affect the gastrointestinal tract of adult mice.

In vitroeffect of two commercial anti-coccidial drugs against myxospores ofKudoa septempunctatagenotype ST3 (Myxozoa, Multivalvulida)

“…1A), which was consistent with previous reports [1, 7]. Control spores with nuclei exhibiting only blue fluorescence (Hoechst 33342 positive and PI negative) were considered viable (Figs.…”

“…2). The gene sequences obtained showed 100% similarity with those of cox1 -3 (KU163620) and rnl -2 (KU163621) belonging to the ST3 genotype [1, 7]. …”

“…The spore genotypes were assessed by conventional PCR to amplify the cytochrome c oxidase subunit I ( cox 1 ; 751 bp) and large subunit rRNA ( rnl ; 817 bp) of the K. septempunctata mitochondrial gene [17]. The primer sets used were cox 1 -F1 (5′-TTTGTTCATCGGCACAATTC-3′), cox 1 -R1 (5′-ATAGCCTGGAACAAGGAATC-3′), rnl -F1 (5′-TGCCGTCATTCTGTTGTATT-3′), and rnl -R1 (5′-AATACCCATGCTGTGTTCAT-3′), as described in previous reports [1, 7, 17]. Negative controls (without template DNA) were included to check for contamination.…”

“…K. septempunctata spores have been isolated from raw olive flounder within 20 h after the fish was consumed by patients who developed diarrhoea, and the patients recovered completely within 24 h, suggesting that K. septempunctata spores are associated with transient clinical symptoms [10]. Several studies have reported clinical symptoms in animal models including the mouse [1, 7, 10], and permeability increase in the human intestinal epithelial monolayer [14]. Few reports on detection methods for K. septempunctata are available [10, 15, 16].…”

Analysis of Kudoa septempunctata as a cause of foodborne illness and its associated differential diagnosis

“…Its pathogenicity to humans has been difficult to verify, and the animal-based studies revealed contradicting results, as discussed by Chung et al [ 6 ]. The results of the pathogenic identification method that focused on K. septempunctata in the clinical samples of patients also contradict the findings in the study conducted by Ahn et al [ 14 ] where K. septempunctata DNA was detected in mice without gastrointestinal symptoms. Therefore, based on these considerations, K. septempunctata may exist in fecal samples of patients who consumed olive flounders infected with the parasite, regardless of the development of food poisoning.…”