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![(A to C) Spores of H. salminicola from a human stool specimen (A) and from sockeye salmon (dorsal view [B] and lateral view [C]), as viewed under a bright-field microscope. (D) Scanning electron micrograph of a spore of H. salminicola from a human stool specimen. (E) Normal human spermatozoa. Bars: panels A to C and E, 10 m; panel D, 5 m.](profile/David-Cone/publication/13878108/figure/fig1/AS:282688507400194@1444409600313/A-to-C-Spores-of-H-salminicola-from-a-human-stool-specimen-A-and-from-sockeye-salmon.png)
(A to C) Spores of H. salminicola from a human stool specimen (A) and from sockeye salmon (dorsal view [B] and lateral view [C]), as viewed under a bright-field microscope. (D) Scanning electron micrograph of a spore of H. salminicola from a human stool specimen. (E) Normal human spermatozoa. Bars: panels A to C and E, 10 m; panel D, 5 m.
Source publication
The spores of Henneguya salminicola, a common tissue parasite of salmonid fishes in the northern hemisphere, were observed in stool specimens from two different patients with diarrhea. The spores' superficial resemblance to human spermatozoa resulted, in one instance, in an incorrect report, leading to suspicion of sexual abuse. H. salminicola spor...
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... resembling human spermatozoa were observed in fecal concentrates at a magnification of 400. They were about 40 m in total length, with a teardrop-shaped spore body approximately 10 m in length which tapered gradually to one or two caudal filaments (Fig. 1A). When viewed laterally, some of the spores were lemon shaped while others, having collapsed, appeared concave, or cup shaped. Most of the spores had two pyriform polar capsules located in the anterior region of the spore ...
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... morphology of the spores was compared with that of previously identified specimens of H. salminicola (Fig. 1B and C). This comparison confirmed that the organisms in the stool specimens were identical to spores of that myxozoan parasite. Scanning electron microscopy showed that the spores had a smooth outer coat and that the caudal filaments were contin- uous with the spore body (Fig. 1D). These characteristics are consistent with the identification ...
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... with that of previously identified specimens of H. salminicola (Fig. 1B and C). This comparison confirmed that the organisms in the stool specimens were identical to spores of that myxozoan parasite. Scanning electron microscopy showed that the spores had a smooth outer coat and that the caudal filaments were contin- uous with the spore body (Fig. 1D). These characteristics are consistent with the identification of H. salminicola. Compari- son with normal human spermatozoa revealed significant dif- ferences in size and structure (Fig. ...
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... parasite. Scanning electron microscopy showed that the spores had a smooth outer coat and that the caudal filaments were contin- uous with the spore body (Fig. 1D). These characteristics are consistent with the identification of H. salminicola. Compari- son with normal human spermatozoa revealed significant dif- ferences in size and structure (Fig. ...
Citations
... (KAWAI et al., 2012). É importante ressaltar que os estudos indicam não haver implicações clínicas relacionadas à ingestão acidental desse parasita (MCCLELLAND et al., 1997;BOREHAM et al., 1998;BRADBURY et al., 2015). ( ...
O tambaqui é a segunda espécie mais produzida no Brasil. A ocorrência de doenças através das infecções parasitárias pode inviabilizar o sucesso da piscicultura. Nesse contexto, o presente estudo teve como objetivo realizar uma revisão sistemática de trabalhos publicados de 2000 a 2021 sobre parasitas em tambaqui (Colossoma macropomum) em piscicultura na Amazônia Brasileira. Como estratégia metodológica foi realizada uma busca sistemática nas plataformas Google Acadêmico, Scielo, PUBMED, BVS. Foram utilizados os descritores Colossoma macropomum, tambaqui, parasite Colossoma macropomum, parasitas em tambaqui. Foram encontrados 35.980 artigos no Google Acadêmico, 302 no Scielo, 389 no PUBMED, e 763 BVS sendo selecionados 21 artigos. Os estados do Pará (36,1%) e Amazonas (26,2%) são os que possuem maior quantidade de trabalhos científicos sobre a ictiofauna do tambaqui em piscicultura. Em relação a presença de parasitos, foram relatadas 36 espécies, sendo a mais frequente A. spathulatus, encontrados nos estados do Amapá, Amazonas, Pará e Rondônia. Os órgãos mais afetados por parasitas foram as brânquias (31,4%), seguido de intestino (11,8%).
... VOL. 49(2) 2019: 162 -165 ACTA AMAZONICA Myxospores of Myxozoa have been incidentally found in human fecal samples, which were collected to investigate soil-transmitted helminthiases or intestinal diseases caused by protozoa of medical importance (Bradbury et al. 2015;McClelland et al. 1997). The presence of myxospores in human feces has been associated with ingestion of contaminated food or undercooked fish (Kawai et al. 2012). ...
... The presence of myxospores in human feces has been associated with ingestion of contaminated food or undercooked fish (Kawai et al. 2012). Infections in humans are considered accidental and without association with clinical manifestations (Bradbury et al. 2015;McClelland et al. 1997;Boreham et al. 1998). Although association of the parasite with gastrointestinal disorders has been reported (Moncada et al. 2001;Kawai et al. 2012), a causal relation with myxospores could not be established due to the concomitant presence of other enteric pathogens (Hessen and Zamzame 2004). ...
... We must also consider that the presence of myxospores may lead to erroneous diagnoses in pathology laboratories that examine human stools due to possible confounding interpretations with other structures (McClelland et al. 1997), or even leading to concerns of a new, previously unidentified protozoan species infecting humans rather than an artefact caused by the passage of fish parasitic spores. ...
Most species of Myxobolus (Cnidaria: Myxozoa) infect freshwater and marine fish, and cause sporozoosis. Passage of myxozoan parasites into human feces has been described occasionally. We examined fecal samples from 97 dwellers of a riverine community in Amazonas State (Brazil), which revealed Myxobolus sp. in 13 (13%) samples. The discovery probably does not represent true parasitism as the myxospores - most likely ingested through the consumption of infected fish - were eliminated unchanged after passing through the gastrointestinal tract. This discovery represents the first report of this myxosporean in human fecal samples in Brazil.
... For the consumer, parasitic infections associated with the ingestion of fish typically go unnoticed, due to the reduced risk of symptoms, and the lack of knowledge, not only of specialists and sanitary inspectors, but also the consumers themselves (Santos 2017). Myxosporidiosis can sometimes occur in humans, as the result of incidental contagion, given that spores have been observed in the faeces of patients, that probably acquired the parasites through the ingestion of infected fish (McClelland, Murphy & Cone 1997;Boreham et al. 1998, Moncada et al. 2001. ...
Mullets (Mugilidae) are economically-important fish exploited extensively by artisanal fisheries on the Amazon coast of Brazil. In the present study, 150 specimens of redeye mullet (Mugil rubrioculus) acquired from the public fish market were examined, and the gill filaments of 90 (60%) were found to be infected with spores of Myxobolus. The mature spores were spherical, with a mean diameter of 6.28±0.33 μm, and had polar capsules of equal size (2.47±0.34 μm in length and 1.58±0.27 μm in width). The 18S rRNA sequence of the parasite was compared with those of other myxosporidian species available in the GenBank database. The morphological and molecular characteristics of the parasite indicate strongly the existence of a new species, denominated Myxobolus bragantinus n. sp., the first case of a new myxosporidian species to be found in this host. [Zoobank: urn:lsid:zoobank.org:act:E00F72E1-9302-423F-BA4E-51C05D0770C8]
... Myxospores have been detected in faeces of patients presenting abdominal pain and/or diarrhea, and from immunocompromised individuals. The first report of myxospores in humans was of the salmonid fish parasite Henneguya salminicola in stool samples of two Canadian patients with diarrhea; one sample was misidentified initially due to its resemblance to human spermatozoa (McClelland et al. 1997). The myxospores were likely ingested as part of infected fish flesh and passed through the gut undigested. ...
Discoveries published in 2007 and 2008 expanded the known host range of
myxozoans beyond poikilotherms to include mammals and birds. Here we
review records of myxozoans from small terrestrial mammals, waterfowl and
those associated with humans, and augment them with data from our ongoing
studies. True myxosporean infections—those with active parasite development
and sporogenesis—have been recorded for Soricimyxum spp. in central
European shrews and Myxidium spp. in North American waterfowl. In all
cases, bile ducts within the liver were the nidal tissue and complete life cycles
are unknown. Incidental myxosporean infections—the presence of myxospores
without parasite development—have been observed in humans,
usually in association with the ingestion of infected fish. Clinical presentations
of these cases range from no disease (e.g. Henneguya spp.), allergic
responses (Kudoa sp.) or acute gastroenteritis (Kudoa septempunctata).
Phylogenetically, myxosporean parasites of homeotherms cluster closely
with Myxidium and Cystodiscus species known to infect other terrestrial
vertebrates (reptiles and amphibians), which suggests a single evolutionary
expansion from an aquatic Myxidium-clade ancestor to semi-aquatic and
terrestrial hosts and environments. Given the diversity of potential
mammalian and avian hosts, we expect additional myxosporean parasites
to be discovered with further scrutiny of these homeotherms, especially in
sparsely surveyed regions including Africa and South America.
... 38 Other anecdotal observations of transient passage or true human infection with myxozoan parasites have been described throughout the literature and this genus has been implicated as a true parasite of immune-compromised humans. [39][40][41] Incidentally, toxins from another myxozoan, Kudoa septempunctata have recently been identified as the cause of food poisoning outbreaks in Japan, but in the absence of intestinal colonization. 42 Follow-up testing did not show any further spores, and it is likely that this case represented transient passage of spores rather than true intestinal colonization. ...
Ongoing surveillance of enteric pathogens of public health significance amongst casual food sellers is undertaken in many resource-limited countries. We report the results of a survey in Kiang West province, The Gambia and provide an exemplar methodology for such surveys in resource-limited laboratories.
Unpreserved, unrefrigerated stool samples were subjected to Salmonella, Shigella and agar plate culture for rhabditoid nematodes. Direct microscopy, formalin-ethyl acetate concentration and iron-hematoxylin staining was performed later, following preservation.
Of 128 specimens received, no Shigella spp. was recovered, while four serovars of non-typhoidal Salmonella enterica, including Chandans, were isolated. Pathogenic parasitic infections were; Necator americanus 10/128 (7.8%), Strongyloides stercoralis 3/128 (2.8%), Blastocystis species 45/128 (35.1%), Entamoeba histolytica complex 19/128 (14.8%) and Giardia intestinalis 4/128 (3.1%). A single case each of Hymenolepis diminuta and S. mansoni infection were detected. In one participant, myxozoan spores identical to those of Myxobolus species, were found.
Rare parasitoses and serovars of Salmonella enterica may occur relatively commonly in rural Africa. This paper describes intestinal pathogens found in a cohort of food sellers in such this setting. Furthermore, it describes two parasites rarely recovered from humans and demonstrates the need for methods other than microscopy to detect S. stercoralis infections.
© The Author 2015. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
... Other case reports, such as some in Australia involving eating fish that had been frozen, exist but probably do not represent human infections [125]. Spores of Henneguya salminicola also have been reported from human diarrheic feces [126,127]. Patients had been eating salmon, and, in one case, the spores were misdiagnosed as human sperm, resulting in scandalous consequences [126]. ...
... Spores of Henneguya salminicola also have been reported from human diarrheic feces [126,127]. Patients had been eating salmon, and, in one case, the spores were misdiagnosed as human sperm, resulting in scandalous consequences [126]. ...
... This accounts for 9.5% of the total number of myxosporeans, relatively less than the species of the largest genus Myxobolus Bütschli, 1881. This genus is widespread and predominantly infects marine and freshwater fishes (Eiras 2002), except for H. salminicola, which is found not only in fish but also in human beings (McClelland et al. 1997;Lebbad and Willcox 1998). The complete life cycle of Henneguya is known only for three species, namely, Henneguya exilis (Lin et al. 1999), Henneguya ictaluri (Pote et al. 2000), and Henneguya nuesslini (Kallert et al. 2005). ...
Henneguya doneci Schulman, 1962 was collected from the gill filaments of Carassius auratus gibelio (Bloch) in Hubei Province, China. The plasmodia located on the surface of the gill arches deformed the neighboring gill filaments. The size of the plasmodia ranged from 0.6 to 4.5 mm in diameter in different months. The myxospores in the plasmodia measured 10.1 (9.2-11.5) μm long × 8.0 (7.5-8.5) μm wide × 7.5 (7-8) μm thick, with two equal capsules at 4.7 (4-5.5) μm long × 3.3 (2.5-4) μm wide, and two caudal processes 32.7 (24-38.5) μm long, respectively. Polar filaments were coiled 5-6 turns. Ultrastructural observation of the plasmodia showing the capsulogenesis of H. doneci is described briefly. The external tubule initially invaginated into the polar capsule. The rudimentary polar filaments were observed to undergo a series of considerable modification, finally developing into mature polar filaments. Molecular analysis demonstrated that although the myxosporean species were collected from different tissues of hosts in various geographic locations, they clustered with the Cyprinidae-infecting myxosporean species in the phylogenetic tree.
... Mature spores stain weakly with hematoxylin and eosin, but are strongly acid-fast (Gardiner et al. 1998). Myxozoan fish parasites have been found in human fecal samples (McClelland et al. 1997, Boreham et al. 1998, Moncada et al. 2001). Moncada et al. (2001) reported spores belonging to the genus Myxobolus based on morphology visible by light microscopy, but only in specimens stained by acidfast techniques. ...
Many bacterial and protozoan pathogens in fish and shellfish exhibit acid-fast staining characteristics that are important for pathogen identification and disease diagnosis. The classic acid-fast staining techniques for light microscopy use carbol-fuchsin; a major ingredient of this stain is caustic and hazardous phenol. A new technique using heated aqueous basic fuchsin can stain two acid-fast human pathogens, Mycobacterium tuberculosis and M. avium. This method is a potentially valuable and safer diagnostic tool for aquatic pathologists. M. marinum, a finfish pathogen, and various additional acid-fast parasitic pathogens of finfish and marine invertebrates were stained successfully using this heated aqueous basic fuchsin method.
... Homeothermic vertebrates, namely mammals, have been reported to harbour myxozoan parasites but most of these may be considered incidental or aberrant host records. In cases where putative myxozoan developmental stages were observed, either mature spores or molecular evidence to confirm their identity as myxozoans were missing, and conversely, on occasions when spores were observed, developmental stages indicating true host status, rather than incidental passage, were absent (McClelland et al., 1997;Boreham et al., 1998;Lebbad and Willcox, 1998;Friedrich et al., 2000;Moncada et al., 2001). However, both developmental stages and mature spores of a new myxosporean, Soricimyxum fegati, were recently described from shrews (Prunescu et al., 2007;Dyková et al., 2007), providing evidence that these parasites may also occur in terrestrial hosts. ...
Myxozoans are spore-forming, metazoan parasites common in cold-blooded aquatic vertebrates, especially fishes, with alternate life cycle stages developing in invertebrates. We report nine cases of infection in free-flying native and captive exotic ducks (Anseriformes: Anatidae) from locations across the United States and describe the first myxozoan in birds, Myxidium anatidum n. sp. We found developmental stages and mature spores in the bile ducts of a Pekin duck (domesticated Anas platyrhynchos). Spores are lens-shaped in sutural view, slightly sigmoidal in valvular view, with two polar capsules, and each valve cell has 14-16 longitudinal surface ridges. Spore dimensions are 23.1 microm x 10.8 microm x 11.2 microm. Phylogenetic analysis of the ssrRNA gene revealed closest affinity with Myxidium species described from chelonids (tortoises). Our novel finding broadens the definition of the Myxozoa to include birds as hosts and has implications for understanding myxozoan evolution, and mechanisms of geographical and host range extension. The number of infection records indicates this is not an incidental occurrence, and the detection of such widely dispersed cases suggests more myxozoans in birds will be encountered with increased surveillance of these hosts for pathogens.
... The importance of these species as pathogens of freshwater fish has been described by several authors 18 . In 1997, occur the report of spores of Henneguya salminicola in human stool specimens, but no exist evidence that these parasites are capable of causing disease in humans 19 . ...
Two new species of Henneguya (Myxozoa) were described from specimens collected on the gills of Hoplosternum littorale (Hancock, 1828) (Callichthyidae) and Cyphocharax gilbert (Quoy and Gaimard, 1824) (Curimatidae), from Guandu River, State of Rio de Janeiro, Brazil. The species described were compared with the related species of the genus. The new species of Henneguya parasitic on H. littorale has cysts with synchronous development, the spore body was 14.6 (11.4-16.7) /urn long by 6.5 (4.9-7.9) μm wide. The total length of the spore was 33.6 (27.3-38.1) ¡mi and each valve had a caudal process measuring 19.0 (15.6-22.5) μm. The larger polar capsule was 4.4 (3.3-5.6)μm long by 2.0 (1.6-2.3) μm wide, the smaller polar capsule was 4.1 (3.3-5.3) ¡mi long by 2.2 (1.5-2.8) fum wide. Each polar filament with 3-6 coils. The new species of Henneguya parasitic on C. gilbert has cysts with synchronous development, the spore body was 11.3 (7.7-13.4) ¡mi long by 4.4 (2.9-6.3) μm wide. The total length of the spore was 35.1 (29.6-44.4) μm and each valve had a caudal process measuring 23.7 (20.8-31.5) μm. The larger polar capsule was 5.2 (4.2-6.3) μm by 1.9 (1.5-2.3) μm wide, the smaller polar capsule was 4.5 (3.4-5.2) ¡mi long by 1.7 (1.3-2.2) ¡mi wide. Each polar filament with 7-9 coils. The characteristics of these species were compared with all the species described so far.
