Sarcocystis sp. shed by the common boa snake (Boa constrictor) in Brazil

The genus Sarcocystis contains around 200 species and 25 of these infect snakes. Two Sarcocystis spp. shed by snakes have called special attention of the scientific community. S. nesbitti, which is shed by scrub pythons (Simalia amethistina), causes myopathy in humans that consume water or food contaminated with the parasite. Sporocysts of S. singaporensis, excreted by reticulated pythons (Malayopython reticulatus), is letal for rats and was successfully tested in the biological control of these rodents. A high biodiversity of snakes is found in Brazil, however, scarce information is available about Sarcocystis spp. in Brazilian snakes. Herein, we investigated Sarcocystis sp. in feces of the common boa (Boa constrictor) from Salvador, as it is widely distributed in Brazil and it is also bred in other countries. Feces of 65 boas were examined, and Sarcocystis sp. was found in 1/65 (1.53%) snakes. All snakes were alive, and for this reason, intestinal scrapping, which is the most sensitive method to detect the parasite, was not performed. Morphometric evaluation of sporocysts showed significant differences in their sizes. PCR and multilocus sequencing of four genetic markers (cox1, 18S, ITS1, and 28S) revealed that sporocysts corresponded to a new Sarcocystis species. Sequences of cox1 and 18S had identities of 100% and higher than 98%, respectively, with sequences obtained from the rodent Lagostomus maximus in Argentina. ITS1 and 28S sequences did not match with any known Sarcocystis sp. No ITS1 and 28S sequences were available for the Sarcocystis sp. found in the Argentinian L.maximus. Bioassay using the boa sporocysts was conducted in three mouse lineages and in Rattus norvegicus, but no parasitic stages were detected in these rodents. We concluded that the common boa is probably the definitive host of a new species of Sarcocystis sp. that has L. maximus or related rodents as intermediate hosts.

Cloning and expression of a cDNA coding for Eimeria acervulina 25 kDa protein associated with oocyst and sporocyst walls

The purpose of this study was to characterize a gene named EAH 00033530 identified by RNAseq analysis of sporulating Eimeria acervulina oocysts and its encoded protein. Quantitative RT-PCR analysis revealed peak expression of EAH 00033530 mRNA early (3-6 h) in sporulation followed by downregulation at 12-24 h. The gene for EAH 00033530 was expressed in Escherichia coli as a 70 kDa polyHis fusion protein (rEAH 00033530). Antisera prepared against rEAH 00033530 protein identified in immunoblotting a native 25 kDa E. acervulina protein (Ea25) that was present in oocyst-sporocyst extracts after treatment with the reducing agent DTT. Immunofluorescence staining using anti-rEa25 localized the protein to both E. acervulina oocyst and sporocyst walls, but not to sporozoites. The protein may be produced during in vivo oocyst development because immunostaining of duodenal tissue from E. acervulina-infected chickens revealed oocyst wall expression. As observed by ELISA, rEa25 protein appears to elicit a humoral immune response in chickens infected with non-irradiated or radiation-attenuated E. acervulina oocysts.

Effect of household bleach on the structure of the sporocyst wall of Toxoplasma gondii

Toxoplasma gondii oocysts are responsible for food- and water-borne infections in humans worldwide. They are resistant to common chemical disinfectants, including chlorinated products, presumably due to the structure and molecular nature of the oocyst wall but also the sporocyst wall. In this study, we used fluorescence microscopy and transmission electron microscopy to characterise the structure of both the oocyst and sporocyst walls, exposed to household bleach. Bleach removed the outer layer of the oocyst wall and the outer layer of the wall of sporocysts exposed due to rupture of the oocyst wall. The loss of the outer sporocyst wall layer was associated with a decrease in its autofluorescence, which can be linked to the degradation of dityrosine cross-link proteins, and loss of Maclura pomifera lectin-reactive glycoproteins. This study suggests that the inner layers of the oocyst and sporocyst walls are the main structures responsible for the resistance of the parasite to household bleach.

Characteristic Light and Electron Microscopic Features of Adelina melolonthae, a Coccidian Pathogen of the European Cockchafer, Melolontha melolontha (Coleoptera/Scarabaeidae)

PURPOSE

The aim of this study was to investigate and document the characteristic electron microscopic features of the oocyst of Adelina melolonthae, a coccidian pathogen of the European cockchafer, Melolontha melolontha (Coleoptera: Scarabaeidae).

METHODS

Larvae of M. melolontha were collected at Ordu, Turkey. Each larva was dissected in insect Ringer solution. Adeleid oocysts from the tissue that is suspected to Contain coccidian infections were examined under a light microscope (Zeiss), a scanning electron microscope (FEI Quanta 200) and transmission electron Microscope (Philips EM 208).

RESULTS

Spherical to ellipsoidal oocysts measure ca. 24-44.5 µm (mean 35.6 µm) in diameter (n = 50) and include up to twelve sporocysts. The oocyst wall has double layers; the outer layer measured 400-500 nm in thickness and the inner one 10-25 nm. Sporocysts including two sporozoites are rounded ca. 11-12.5 µm (mean 11.7 µm) in diameter. The sporocyst wall consisted of only one 70-80-nm-thick layer. The sporozoites are ellipsoidal and measured 9-11 µm length and 3-4 µm in width. Sporocysts include residual bodies.

CONCLUSION

In the present paper, the morphology and ultrastructure of the oocyst of A. melolonthae is documented for the first time and compared with other Adelina and coccidian species infecting insects. The results in this study confirm his identification and justify the classification as a separate species A. melolonthae, which differs from other Adelina species.

First record and distribution of Adelina sp. (Coccidia: Adeleidae) in populations of the Anisoplia segetum Herbst (Coleoptera: Scarabaeidae) in Turkey

In this study, an Adelina sp. (Coccidia) infection was determined for the first time from Anisoplia segetum (Coleoptera: Scarabaeidae). The infection was observed in the gut and fat body of the host. The determined oocysts were ellipsoidal and measured 36.3 (34-38) × 30.2 (27-32) μm. The number of sporocysts per oocyst varied from 7 to 15. The dizoic sporocysts were usually subspherical, 10.2 (9-12) × 8.9 (8-10) μm. Also, some developmental stages and unsporulated oocysts were determined with electron microscopical observations. The immature microgamonts were observed in different shapes, from ovoid to spherical. And the detected oval unsporulated oocyst was measured 4.9 μm in length and 3.6 μm in width. The formation and distribution of these pathogens were also presented in A. segetum populations.

Three new species of virgulate xiphidiocercariae infecting the freshwater snails of Kerala

Three new species of virgulate xiphidiocercariae infecting the freshwater snails of Malabar, Kerala is described. Cercaria sp. XXVI Malabar n. sp. recovered from Bellamya bengalensis collected from Malappuram district of Kerala is characterized by an elongate-oval, spinose body and a highly contractile and spinose tail; dagger-shaped stylet with reinforced walls; coma-shaped virgula organ; muscular pharynx; short, narrow oesophagus; three pairs of penetration glands; bean-shaped excretory bladder and 12 pairs of flame cells. Cercaria sp. XXVII Malabar n. sp. recovered from Thiara tuberculata collected from Wayanad district of Kerala has a round to elongate-oval, spinose body; a highly contractile, spinose tail; dagger-shaped stylet; muscular pharynx; short oesophagus; narrow caeca extending up to ventral sucker; three pairs of penetration glands; bicornuate, thin-walled excretory bladder, and 12 pairs of flame cells. Cercaria sp. XXVII Malabar n. sp. infecting Paracrostoma huegelii also collected from Wayanad district, Kerala is characterized by elongate-oval, spinose body; contractile and spinose tail; dagger-shaped, inwardly curved stylet; virgula organ with elongated lobes; globular pharynx; three pairs of penetration glands; bicornuate, transversely elongate excretory bladder and 18 pairs of flame cells. All the three cercariae developed in sporocysts within the heapatopancreatic tissues of their respective snail hosts. The cercariae were compared with related species to establish their systematic position.

In vivo cultivation of tuna blood fluke Cardicola orientalis in terebellid intermediate hosts

Some fish blood flukes of the genus Cardicola (Aporocotylidae) are considered important pathogens of farmed/ranched tuna, Thunnus spp. Infections with Cardicola spp. might obstruct the blood flow in the gills via massive accumulations of eggs and often lead to mass mortalities in captive tuna. At present, oral administration of an anthelminthic drug, praziquantel is the most effective treatment, but the tuna farming industries are seeking non-drug control measures. Development of prophylactic and holistic measures have been difficult, owing to a lack of basic knowledge about these parasites. Unlike other trematodes which use molluscs, blood flukes of marine actinopterygian fish use terebellid polychaetes as intermediate hosts. However, information about the development of Cardicola spp. within intermediate hosts is very limited. Recent success in Cardicola opisthorchis sporocyst transplantation into the host polychaete has opened possibilities for the cultivation of Cardicola in the laboratory. Here, we conducted several transplantation trials with another tuna blood fluke, Cardicol orientalis, into its natural and surrogate polychaete hosts. Cardicola orientalis sporocysts were injected into a total of 195 Nicolea gracilibranchis, the natural host, and clear sporocyst development and reproduction was observed in 32 recipients (overall success rate 16.4%). The production of daughter sporocysts in the transplanted polychaete occurred within 14 days post injection, and one sporocystogenous cycle took approximately 4 weeks. Serial passage culture via transplantation of in vivo-cultured sporocysts was also achieved, but with limited sporocyst reproduction. In addition, sporocysts were successfully retrieved from six and one individuals of the surrogate hosts, Thelepus setosus (n = 10) and Thelepus japonicus (n = 5), respectively. These results indicate that the in vivo cultivation of C. orientalis sporocysts is possible, not only in its natural host but also in other terebellids, although the problems of high mortality and inconsistency in successful transplantation need to be resolved.

Four new species of virgulate xiphidiocercariae infecting the freshwater snail, Bithynia (Digoniostoma) pulchella (Benson, 1836) in Malabar, Kerala

The present paper describes four new species of virgulate xiphidiocercariae infecting the freshwater gastropod, Bithynia (Digoniostoma) pulchella (Benson, 1836) collected from Malabar, Kerala. Cercaria sp. XXII Malabar n. sp. has a spinose body and tail; four pairs of penetration glands; short, narrow oesophagus; a pair of short, unequal caeca; bicornuate excretory vesicle and 18 pairs of flame cells. Cercaria sp. XXIII Malabar n. sp. is characterized by an oval, spinose body; aspinose tail; dagger-shaped stylet; medially fused virgula; globular pharynx; short oesophagus; three pairs of penetration glands; bicornuate, 'V'-shaped excretory bladder, and 18 pairs of flame cells. Cercaria sp. XXIV Malabar n. sp. has a spinose body and tail, medially fused virgula, muscular pharynx, short prepharynx and oesophagus; four pairs of penetration glands; bicornuate, 'V'-shaped excretory bladder, and 12 pairs of flame cells. Cercaria sp. XXV Malabar n. sp. has a spinose body, aspinose tail, sac-like virgula; globular pharynx, narrow oesophagus; short caeca; four pairs of penetration glands; transversely elongated, bicornuate excretory bladder, and 12 pairs of flame cells. All four cercariae developed in sporocysts within the digestive gland of B. (D.) pulchella. Morphology and morphometry of the cercariae are compared with related species to establish their systematic position.

Sarcocystis falcatula-like derived from opossum in Northeastern Brazil: In vitro propagation in avian cells, molecular characterization and bioassay in birds

Most reported isolates of Sarcocystis spp. derived from Brazilian opossums (Didelphis sp.) have genetic characteristics distinct from the known species of Sarcocystis, but behave similarly as Sarcocystis falcatula, as they are infective to budgerigars. In previous studies, these Brazilian isolates, classified as Sarcocystis falcatula-like, were originated from South and Southeast regions of Brazil. In the current work, we aimed to culture and to perform multilocus sequence analysis of Sarcocystis sp. derived from a Brazilian opossum (D. aurita/D. marsupialis) that inhabited the city of Salvador, Bahia, in the Northeast of Brazil. The parasite was isolated in Vero cells, referred here as Sarco-BA1, and propagated in avian cells (DF-1). Molecular analysis of Sarco-BA1 revealed that the nucleotide sequence of the internal transcribed spacer 1 (ITS1) of the rDNA was identical to all isolates (n = 19) of Sarcocystis spp. reported in two studies from South and Southeast regions of the country. Two budgerigars were inoculated with 10 and 1000 sporocysts of Sarco-BA1, respectively, and developed acute sarcocystosis, showing that the parasite behaves like S. falcatula. It was interesting to observe that Sarco-BA1 had almost identical ITS1 and SAG sequences to all 16 isolates of S. falcatula-like recently described in Magellanic penguins (Spheniscus magellanicus) rescued on the coast of Espírito Santo state, Brazil. Our results suggest that Sarco-BA1 and S. falcatula-like may represent a single species of Sarcocystis. Propagation of the parasite in a permanent avian cell line significantly improved the yield of merozoites in cell culture. To our knowledge, this is the first molecular study and in vitro isolation of S. falcatula-like derived from Northeastern Brazil. Studies are under way to determine the infectivity of Sarco-BA1 to other animal species, as well as to investigate serological cross-reactivity among Sarco-BA1, S. neurona and related species.

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Sarcocystis falcatula-like was isolated for the first time in Northeastern Brazil.

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Its genetic pattern was similar to isolates from South and Southeastern Brazil.

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A permanent avian cell line was successfully used to propagate the parasite.

New species of macrocercous and megalurus cercariae infecting the freshwater snail, Paludomus (Paludomus) tanschauricus (Gmelin, 1771) in Malabar, Kerala

The present paper describes two new species of cercariae infecting the freshwater snail, Paludomus (Paludomus) tanschauricus from Malabar, Kerala. Paludomus tanschauricus collected from the hill streams at Vattakkundu in the Wayanad district of Kerala harboured a macrocercous cercaria, Cercaria sp. XX Malabar n. sp. characterized by a disproportionately large tail. Developmental stages were recovered from the hepatopancreatic tissues of the snail host. Cercariae encysted on the gills of the fish, Haludaria melanampyx. Snails collected from Papanashini rivulet at Thirunelli, also from Waynad district were infected with a megalurous cercaria, Cercaria sp. XXI Malabar n. sp. possessing an elongated tail with an adhesive cup-like sucker at its tip. Redial stages developed in the hepatopancreas while the cercariae were found to encyst on any available substrate. The morphology and morphometry of these two cercariae along with their developmental stages are studied in detail and compared with related species to establish their systematic positions.

Furcocercous cercariae infecting freshwater snails in Malabar: two new species from Lymnea luteola Lamarck and Gyraulus convexiusculus (Hutton)

The present paper describes two new species of furcocercous cercariae, Cercaria sp. XVIII Malabar n. sp. and Cercaria sp. XIX Malabar n. sp. infecting the freshwater snails, Lymnea luteola and Gyraulus convexiusculus respectively in the Malabar region of Kerala. Cercaria sp. XVIII Malabar n. sp., is a distome, pharyngeate, non-ocellate, longifurcate furcocercous cercaria with two pairs of penetration glands and 16 pairs of flame cells and recovered from L. luteola. Cercaria sp. XIX Malabar n. sp., is also a distome, pharyngeate, longifurcate cercaria with a pair of unpigmented eyespots and 20 pairs of flame cells and recovered from G. convexiusculus. Sporocysts of both the cercariae developed in the digestive glands. The present paper describes the cercariae and compares them with related species to establish their systematic position.

Two new species of furcocercous cercariae infecting the fresh water snail, Thiara tuberculata (Müller) in Kozhikode and Malappuram districts of Kerala

Two new species of furcocercous cercariae, Cercaria sp. XVI Malabar n. sp. and Cercaria sp. XVII Malabar n. sp. were recovered from the freshwater snail, Thiara tuberculata in the Malabar region of Kerala. Cercaria sp. XVI Malabar n. sp., a pharyngeate, longifurcate furcocercous cercaria with two pairs of penetration glands and 10 pairs of flame cells was recovered from T. tuberculata collected from Kundayithode in Kozhikode district and Nilambur in Malappuram district of Kerala. Cercaria sp. XVII Malabar n. sp., another pharyngeate, longifurcate cercaria with a rudimentary ventral sucker was recovered from the same snail host collected from Nilambur in Malappuram district. Sporocysts of Cercaria sp. XVI Malabar n. sp. developed in the hepatopancreas, while that of Cercaria sp. XVII Malabar n. sp. were found developing in both hepatopancreas and stomach wall. The present paper describes the new species of cercariae in detail and compares them with related species to establish their systematic position.

Two new species of xiphidiocercariae from the apple snail Pila virens in Malabar, Kerala

Two new species of xiphidiocercariae, Cercaria sp. XIV Malabar n. sp. and Cercaria sp. XV Malabar n. sp. were recovered from the apple snail Pila virens collected from freshwater bodies in the Malabar region of Kerala. Cercaria sp. XIV Malabar n. sp. was recovered from P. virens collected from Modakkallur in Kozhikode district and Cercaria sp. XV Malabar n. sp. from the same snail species collected from Payyanur in Kannur district. Sporocysts were also recovered from the infected snail hosts. The two new species of cercariae are described in detail and compared with related species to establish their systematic position.

Developmental stages of fish blood flukes, Cardicola forsteri and Cardicola opisthorchis (Trematoda: Aporocotylidae), in their polychaete intermediate hosts collected at Pacific bluefin tuna culture sites in Japan

Farming of Pacific bluefin tuna (PBT), Thunnus orientalis, is a rapidly growing industry in Japan. Aporocotylid blood flukes of the genus Cardicola comprising C. orientalis, C. opisthorchis and C. forsteri are parasites of economic importance for PBT farming. Recently, terebellid polychaetes have been identified as the intermediate hosts for all these parasites. We collected infected polychaetes, Terebella sp., the intermediate host of C. opisthorchis, from ropes and floats attached to tuna cages in Tsushima, Nagasaki Prefecture, Japan. Also, Neoamphitrite vigintipes (formerly as Amphitrite sp. sensu Shirakashi et al., 2016), the intermediate host of C. forsteri, were collected from culture cages in Kushimoto, Wakayama Prefecture, Japan. The terebellid intermediate hosts harbored the sporocysts and cercariae in their body cavity. Developmental stages of these blood flukes were molecularly identified using species specific PCR primers. In this paper, we describe the cercaria and sporocyst stages of C. opisthorchis and C. forsteri and compare their morphological characteristics among three Cardicola blood flukes infecting PBT. We also discuss phylogenetic relations of the six genera of the terebellid intermediate hosts (Artacama, Lanassa, Longicarpus, Terebella, Nicolea and Neoamphitrite) of blood flukes infecting marine fishes, based on their morphological characters.

Human intestinal sarcocystosis in Iran: there but not seen

Human sarcocystosis is a rare infection caused by the genus Sarcocystis who human serve as definitive (intestinal form of infection) host or intermediate (extraintestinal form) host for some various Sarcocystis species. The detection of Sarcocystis oocysts/sporocysts in the feces usually incidentally and is achieved by microscopic examination of the fresh or preserved specimens. To rule out any parasitological etiology among 23,875 (aged 2 months to 95 years) apparently immunocompetent Iranian individuals (from October of 2010 to June of 2016) with abdominal discomforts referred to several teaching hospitals and local clinical laboratories in Fars Province, Iran, their fecal samples were examined using light microscopy. Most pathogenic parasite-positive and doubtful samples were sent to the Intestinal Protozoology Laboratories of Fasa and Shiraz Universities of Medical Sciences to further examination to detect probable co-infection with other underdiagnose parasitoses. In addition to the common protozoal and helminthic infections, during the course of examining stool specimens using direct smear mixed with saline or iodine mounts and by formalin-ethyl acetate techniques, four cases of intestinal Sarcocystis infection as only or concurrently infected with other parasites were found. The present paper presents cases of human intestinal Sarcocystis infection in Iran. Since Sarcocystis are small in size and usually rare in stool, they often go unnoticed. It should be noted that stool smears must be examined with great care to avoid misinterpretation of Sarcocystis infections in microscopic examinations. To the best of our knowledge, co-infection of intestinal sarcocystosis and other principal parasitoses in stool investigations has not been reported earlier.

Characterization of an IgG monoclonal antibody targeted to both tissue cyst and sporocyst walls of Toxoplasma gondii

Toxoplasma gondii infects animals habiting terrestrial and aquatic environments. Its oocysts and tissue cysts are important for the horizontal transmission of this parasite. The oocyst and tissue cyst walls are crucial for the ability of the parasite to persist in the environment or in animal tissues, respectively. However, the composition of these walls is not well understood. We report the generation of monoclonal antibodies directed against wall components using mice immunized with oocyst antigens of T. gondii. One monoclonal antibody (mAb) G1/19 reacted solely with T. gondii sporozoites. The respective antigen had a relative molecular weight (Mr) of 30 kDa. MAb G1/19 failed to react with sporozoites of any other coccidian parasite species tested (Hammondia hammondi, Hammondia heydorni, Cystoisospora felis, Eimeria bovis, Sarcocystis sp.). Another mAb, designated K8/15-15, recognized antigens in sporocyst walls of the parasite and in the walls of in vivo or in vitro produced tissue cysts, as demonstrated by immunofluorescence and immunoblot assays. Antigens of 80 to a high molecular weight protein of about 350 kDa Mr were recognized by this antibody using antigen extracts from sporocysts, and from in vitro or in vivo generated tissue cysts of the parasite. Tissue cyst and sporocyst walls of H. hammondi and H. heydorni, and tissue cysts of Neospora caninum were also recognized by mAb K8/15-15. Sporocyst walls of C. felis also reacted to this mAb. The cyst walls of Sarcocystis sp. and Besnoitia besnoiti were not recognized by mAb K8/15-15. Reactivity by a single mAb against T. gondii antigens in tissue cysts and sporocysts had not been reported previously. MAb K8/15-15 may be a practical tool for the identification of both cysts and sporocysts of the parasite, and may also be potentially employed in proteomic studies on the identification of new components of the cyst and sporocyst walls of T. gondii.

In vitro interactions between the defense systems of resistant and susceptible Biomphalaria alexandrina and sporocysts of Schistosoma mansoni

Biomphalaria species that act as an intermediate host for Schistosoma mansoni have different degrees of susceptibility and different internal defense system responses against parasites. Of these species, Biomphalaria alexandrina represents the only intermediate host in Egypt. Given the limited data on the efficacy of the B. alexandrina internal defense system in comparison to that of other species, we sought to better understand its defense against S. mansoni. We performed in vitro hemocyte adherence assay using whole hemolymph and in vitro reaction using the hemocyte-free hemolymph of susceptible and resistant snails against transformed mother sporocysts. The results demonstrated that the interacting factors between the parasite and the hemolymph of the resistant and susceptible snails do not act in a similar manner. Destruction of the parasite was a restricted function of the hemocytes among resistant snails only. This study demonstrates the key role played by snail hemocytes as a first line of defense against the parasite. The incubation of the hemocyte-free hemolymph of both susceptible and resistant snails with the sporocysts did not lead to any changes in the sporocysts shape or integrity. This immunological variance demonstrated between susceptible and resistant snails could be useful to differentiate between susceptible and resistant snails in future field studies. In addition, the results may help further studies to explain the process of attraction, encapsulation and subsequent killing of S. mansoni in its intermediate host.

Three new species of Xiphidiocercariae from the thiarid snail Thiara tuberculata in Palakkad, Kerala, India

Three new species of Xiphidiocercous cercariae, Cercaria sp. IX Malabar n.sp., Cercaria sp. X Malabar n.sp. and Cercaria sp. XI Malabar n.sp. were recovered from the thiarid snail Thiara tuberculata collected from freshwater bodies in the Palakkad district of Kerala. The three new species are described in detail and compared with their related species to establish their systematic position.