Kudoa ogawai (Myxosporea: Kudoidae) Infection in Cultured Olive Flounder Paralichthys olivaceus

Since Kudoa septempuntata was identified as a causative agent of food poisoning associated with raw olive flounder Paralichthys olivaceus, interest and concern regarding the parasite have increased. However, there have been no investigations or reports of other Kudoa species infecting the fish (except for K. paralichthys, which infects the brain) in Korea. We found cysts filled with myxospores of Kudoa species in muscles of cultured olive flounder specimens and identified these to the species level. Mature spores were quadrate, measuring 8.7±0.5 μm in length, 9.2±0.4 μm in thickness, and 12.9±0.6 μm in width. The spores containing 4 polar capsules had a length of 2.1±0.2 μm and a width of 1.8±0.3 μm. The partial 18S and 28S rDNA of isolates showed 99–100% similarities with K. ogawai. Using these morphological and molecular analyses, the species was identified as K. ogawai. This study is the first report of K. ogawai infection in cultured olive flounder in Korea.

Infection of the muscle tissue of the filter-feeding cichlid, Chaetobranchopsis orbicularis Steindachner, 1875, by Kudoa orbicularis (Myxozoa: Multivalvulidae) on Marajó Island in the Brazilian Amazon region / Infecção por Kudoa orbicularis (Myxozoa: Multivalvulidae) na musculatura de Chaetobranchopsis orbicularis Steindachner, 1875, oriundo da Ilha de Marajó na região Amazônica do Brasil

This study describes aspects of infections caused by the myxosporidian Kudoa orbicularis in filter-feeding cichlids, Chaetobranchopsis orbicularis, caught in the Arari River in the municipality of Cachoeira do Arari, on Marajó Island, Pará, Brazil. The parasite forms pseudocysts scattered throughout the striated epaxial and hypaxial muscles. Samples embedded in paraffin were analyzed histologically using hematoxylin-eosin, Gömöri, Ziehl-Neelsen, and Giemsa staining. Necropsy of the C. orbicularis specimens revealed that 100% (50/50) were infected with K. orbicularis. The specimens presented grossly abnormal muscle texture, resulting in extensive inconsistencies and weakness. Progressive softening of the muscles was observed during necropsy, indicating the rapid enzymatic autolysis of the tissue. The parasite found in the muscle tissue of C. orbicularis was identified as K. orbicularis, with clinical signs of disease being observed in the fish. The necropsy revealed extensive damage to the host organism, with well-established fibrocystic infections in the muscle fibers, associated with post mortem myoliquefaction.(AU)

O presente estudo descreve os aspectos histopatológicos de infecção causada por mixosporídio da espécie Kudoa orbicularis, o qual forma pseudocistos dispersos em toda a musculatura estriada esquelética, epi e hipoaxial, de Chaetobranchopsis orbicularis, capturados no Rio Arari, município de Cachoeira do Arari, Ilha do Marajó, Pará. Foram realizadas as técnicas histológicas de impregnação em parafina, utilizando-se as colorações de hematoxilina-eosina, Gomori, Ziehl-Neelsen e Giemsa. As análises necroscópicas dos espécimes de C. orbicularis revelaram 100% (50/50) de infecção por K. orbicularis. Os espécimes apresentavam macroscopicamente musculatura com características anormais de textura, se mostrava inconsistente e frágil. Durante a necropsia, pôde ser observado um progressivo amolecimento da musculatura, o que demonstra um rápido processo enzimático autolítico. Com base nos achados descritos neste trabalho, caracterizou-se uma infecção da musculatura de C. orbicularis por K.orbicularis, com demonstração de sinais clínicos de doença no peixe; os achados necroscópicos mostraram danos ao organismo hospedeiro, com instalação de infecção fibrosística nas fibras musculares, associada com uma mioliquefação post mortem.(AU)

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

OBJECTIVES: Recently kudoa septempuctata in olive flounders is suggested as a cause of food poisoning, however whether kudoa septempuctata can affect human gastrointestinal systems is controversial and its pathogenecity remains unclear. In view of the field epidemiology, food poisonings caused by kudoa septempuctata should be distinguished from those caused by Staphylococcus aureus and bacillus cereus. METHODS: The statistics of food poisoning investigations published by Korea Centers for Disease Control and Prevention in 2013-2015 were reviewed. The characteristics of kudoa septempuctata food poisoning reported by Korea Centers for Disease Control and Prevention were reviewed. Information regarding clinical symptoms or epidemiology was extracted. RESULTS: Total eleven kudoa septempuctata food poisoning cases were analyzed. Food poisonings caused by kudoa septempuctata, Staphylococcus aureus and bacillus cereus have clinical and epidemiological similarities. Forty five percent of food poisoning outbreaks occurred in Korea was concluded as unknown. The food poisoning caused by Staphylococcus aureus and bacillus cereus accounted for 4.5% (50/1,092) of all food poisoning outbreaks in Korea between 2013 and 2015. CONCLUSIONS: This study suggests the possibilities of misdiagnosis in the investigations of food poisoning by Staphylococcus aureus and bacillus cereus with kudoa septempuctata.

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

OBJECTIVES: Recently kudoa septempuctata in olive flounders is suggested as a cause of food poisoning, however whether kudoa septempuctata can affect human gastrointestinal systems is controversial and its pathogenecity remains unclear. In view of the field epidemiology, food poisonings caused by kudoa septempuctata should be distinguished from those caused by Staphylococcus aureus and bacillus cereus.METHODS: The statistics of food poisoning investigations published by Korea Centers for Disease Control and Prevention in 2013-2015 were reviewed. The characteristics of kudoa septempuctata food poisoning reported by Korea Centers for Disease Control and Prevention were reviewed. Information regarding clinical symptoms or epidemiology was extracted.RESULTS: Total eleven kudoa septempuctata food poisoning cases were analyzed. Food poisonings caused by kudoa septempuctata, Staphylococcus aureus and bacillus cereus have clinical and epidemiological similarities. Forty five percent of food poisoning outbreaks occurred in Korea was concluded as unknown. The food poisoning caused by Staphylococcus aureus and bacillus cereus accounted for 4.5% (50/1,092) of all food poisoning outbreaks in Korea between 2013 and 2015.CONCLUSIONS: This study suggests the possibilities of misdiagnosis in the investigations of food poisoning by Staphylococcus aureus and bacillus cereus with kudoa septempuctata.

Kudoa spp. (Myxozoa, Multivalvulida) parasitizing fish caught in Aracaju, Sergipe, Brazil / Kudoa spp. (Myxozoa, Multivalvulida) parasitando peixes capturados em Aracaju, Sergipe, Brasil

Abstract This study reports on Kudoa spp. (Myxozoa, Multivalvulida) from the fish species Lutjanus analis, Bagre marinus, Aspistor luniscutis and Lutjanus jocu, which were caught in Aracaju, state of Sergipe, Brazil. The parasites formed oval plasmodia around the esophagus of L. analis, and elongated plasmodia inside the skeletal muscle of B. marinus, A. luniscutis and L. jocu. Host myoliquefaction was not observed in all the cases studied. The current study provides a morphological and morphometric description of each parasite as well as a comparison with all the species described worldwide. Lack of molecular data impaired specific identification of the parasites. The importance of these parasites is discussed and the need for further studies on infections in Brazilian fish is emphasized because of the high economic impact of some Kudoa species which cause liquefaction in hosts’ muscles and render these fish unsuitable for consumption.

Resumo Este estudo relata Kudoa spp. (Myxozoa, Multivalvulida) de espécies de peixes Lutjanus analis, Bagre marinus, Aspistor luniscutis e Lutjanus jocu que foram capturados na costa litorânea de Aracaju, Estado de Sergipe, Brasil. Os parasitas formavam plasmódios ovais rodeando o esófago em L. analis, enquanto que nas espécies B. marinus, A. luniscutis e L. jocu formavam plasmódios alongados no interior das fibras musculares. Fenômenos de liquefação do músculo do hospedeiro não foram observados. O presente estudo proporciona uma descrição morfológica e morfométrica de cada parasita, sendo feita uma comparação com todas as espécies conhecidas em todo mundo. A inexistência de dados moleculares prejudica a identificação específica dos parasitas. A importância destes parasitas é discutida e a necessidade de mais estudos relacionados a infecções em peixes brasileiros é enfatizada por causa do alto impacto econômico de algumas espécies de Kudoa que causam liquefação nos músculos dos hospedeiros e tornam estes peixes impróprios para consumo.

Characterization of proteases isolated from Kudoa septempunctata / 대한수의학회지

Proteases play important roles in parasite development and host parasite interactions. The protease of Kudoa spp. has been recognized as a key factor of severe proteolysis of fish muscle post-mortem; however, there is little information available regarding the protease of Kudoa (K.) septempunctata, which was recently identified as a cause of food poisoning in humans. The present study was conducted to isolate and characterize proteases to elucidate the type of protease contained in the parasite and determine the optimal pH for protease activity. We confirmed the cysteine protease and metalloprotease produced by K. septempunctata. While the cysteine protease showed optimal activity at pH 5 that decreased rapidly with increasing pH, the optimal activity of metalloprotease was pH 7, and it remained stable from pH 6 to pH 8. These results indicate that the pH of cysteine protease is not proper for fish muscle postmortem, and that metalloprotease can act in human intestines. Overall, the present study provides important information that improves our understanding of the role of protease physiology and the subsequent food poisoning caused by K. septempunctata.

A note on the infection of Scomberomorus brasiliensis (Osteichthyes, Scombridae) by Kudoa sp. (Myxozoa: Multivalvulida)

The infection of Scomberomorus brasiliensis by the myxozoan Kudoa sp. is reported. The parasites formed plasmodiae inside the skeletal muscle fibres. The spores were quadrate in apical view and bell-like shaped in lateral view, containing four equally sized more or less rounded polar capsules. No detrimental effects were observed in the host, namely muscle liquefaction. The importance of these parasites is discussed.

Relata-se a parasitose de Scomberomorus brasiliensispelo myxozoa Kudoa sp. Os parasitas formavam plasmódios no interior das fibras musculares esqueléticas. Os esporos tinham forma quadrada em observação apical e forma de sino achatado em observação lateral, contendo quatro cápsulas polares do mesmo tamanho e sensivelmente arredondas. Não foram observadas lesões nos hospedeiros, nomeadamente liquefacção do músculo. A importância destes parasitas é discutida

A note on the infection of Scomberomorus brasiliensis (Osteichthyes, Scombridae) by Kudoa sp. (Myxozoa: Multivalvulida) / Nota sobre a infeção de Scomberomorus brasiliensis (Osteichthyes, Scombridae) por Kudoa sp. (Myxozoa: Multivalvulida)

The infection of Scomberomorus brasiliensis by the myxozoan Kudoa sp. is reported. The parasites formed plasmodiae inside the skeletal muscle fibres. The spores were quadrate in apical view and bell-like shaped in lateral view, containing four equally sized more or less rounded polar capsules. No detrimental effects were observed in the host, namely muscle liquefaction. The importance of these parasites is discussed.

Relata-se a parasitose de Scomberomorus brasiliensis pelo myxozoa Kudoa sp. Os parasitas formavam plasmódios no interior das fibras musculares esqueléticas. Os esporos tinham forma quadrada em observação apical e forma de sino achatado em observação lateral, contendo quatro cápsulas polares do mesmo tamanho e sensivelmente arredondas. Não foram observadas lesões nos hospedeiros, nomeadamente liquefacção do músculo. A importância destes parasitas é discutida.