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Photomicrograph of a direct saline smear from a pooled fecal sample of four Morelia viridis showing numerous Sarcocystis sp. sporocysts and a digenean trematode egg.
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SUMMARY Sarcocystis spp. represent apicomplexan parasites. They usually have a heteroxenous life cycle. Around 200 species have been described, affecting a wide range of animals worldwide, including reptiles. In recent years, large numbers of reptiles have been imported into Europe as pets and, as a consequence, animal welfare and species protectio...
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Extensive numbers of Ball pythons are caught, bred, traded and subsequently kept in captivity across the world as part of the exotic pet industry. Despite their widespread availability as pets, relatively little is known about the potential welfare challenges affecting them. We reviewed the literature for research focused on the health and welfare...
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... Classification of most Sarcocystis spp. derived from snakes were based on morphological aspects; as molecular confirmation was not attempted for the majority of sporocysts or oocysts detected in these animals, validation of the species names require further analysis (More et al., 2014). ...
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.
... In addition to the report of S. pythonis in M. spilota (Pythonidae) as an IH, there are also some records of DHs, such as Sarcocystis sp. in M. spilota variegata Gray from Australia (4), and Sarcocystis spp. (KC201639, KC201640) in M. viridis (Schlegel) from Germany (5). ...
Species of Sarcocystis use various vertebrates as intermediate or definitive hosts in their life cycles. One of these is snakes, whose role as intermediate hosts for these protozoans is scarce; in fact, there are six records, but only three with molecular characterization. An imported green tree python was involved in the morphological and molecular characterization (four loci) of a new species of Sarcocystis localized in skeletal muscles. Sarcocystis moreliae sp. nov. has a type 1 sarcocyst with a smooth wall and is genetically similar (at the 18S rRNA gene) to two unnamed species of Sarcocystis found in Lytorhynchus diadema from Oman and Varanus salvator macromaculatus from Malaysia, but their detailed comparison is impossible. The new species showed lower similarity to its congeners in other loci (28S rRNA, ITS1, and cox1). This is the first morphological and genetic characterization of a Sarcocystis species in snakes of the genus Morelia, particularly M. viridis, using four loci, but more data are needed to fill the knowledge gap about snakes as intermediate hosts of Sarcocystis.
... On the contrary, the presence of patent Sarcocystis spp. infection in captive-bred snakes strongly suggests that they are wild-caught (Moré et al., 2014). In this sense, the presence of Sarcocystis sp. in invasive kingsnakes in Gran Canaria suggests that the population was established rather by individuals introduced from wild populations in the southwestern United States of northern Mexico than by captive-borne pet snakes. ...
Invasive species pose a threat not only to biodiversity because they displace or compete with native fauna, but also because of the pathogens they can host. The Canary Islands are an Atlantic biodiversity hotspot threatened by increasing numbers of invasive species, including the California kingsnake Lampropeltis californiae, which was recently introduced to Gran Canaria. Seventy-seven snakes were examined for gastrointestinal parasites in 2019–2020. Sporocysts of Sarcocystis sp. were detected in 10 of them; detection of gamogonia stages in histological sections of 3 snakes confirmed the snake as a definitive host. Partial ssrDNA was amplified using SarcoFext/SarcoRext primers; an additional sequence of Sarcocystis was obtained from the tail muscle of the endemic Gran Canaria giant lizard Gallotia stehlini for a comparison. Identical ssrDNA sequences of unknown Sarcocystis sp. were obtained from 5 different snakes. Phylogenetic analysis showed that Sarcocystis sp. isolated from invasive California kingsnakes is unrelated to Sarcocystis provisionally considered S. stehlini from the endemic lizard. The dixenous coccidia are rarely reported to invade new predator–prey systems. However, the present data suggest that previously unknown Sarcocystis sp. is circulating among invasive snakes and as yet unknown vertebrate intermediate hosts, with undetermined consequences for the Gran Canaria ecosystem.
... Mice breeders declare that their mice are free from parasites and safe to feed to pet snakes. Snakes that are fed with in-house produced mice that are not an intermediate host for Sarcocystis sp. are unlikely to be infected (Moré et al. 2014). ...
Green tree python (Morelia viridis, Schlegel 1872) is a highly sought-after Indonesian/Papuan NG/Australian species in terms of the international trade in reptile pets. As the trade in wild animals is mostly prohibited nowadays, captive breeding supplies the international pet trade. There is evidence that captive breeding might be used as a cover for specimen’s illegally sourced from the wild, as there are very few possibilities of distinguishing wild from captive-bred animals. These rely on invasive sampling (cutting off the end of the tail in order to obtain a sample of blood/muscle/bone tissues) or presence of ecto- and/or endoparasites (method overcome by breeders housing animals in semi wild conditions). Therefore, we examined the possibility of using stable isotope analysis for determining: either the place of origin or diet as a means of defining whether they are captive bred or illegally sourced from the wild. We also review the use of non-invasive samples of shed (moulted) skins. We conclude that shed skins that are currently not used for identifying the source of green tree python could be used as forensic evidence, subject to the development of a viable method.
... First samples were microscopically assessed. For this, samples of heart and skeletal muscles (processed as a pool for each animal) were homogenized in a mixer with PBS and analysed for the presence of cysts of Sarcocystis spp. as previously described (Moré et al., 2011(Moré et al., , 2014. In a second phase, samples of brain, homogenate of heart and pool of skeletal muscles and cystic structures were subjected to DNA extraction with the commercial kit Wizard genomics (Promega) according to manufacturer's instructions. ...
We report on the investigation of a mass stranding of 68 short-beaked common dolphins (Delphinus delphis) that occurred in Golfo Nuevo, Península Valdés, Argentina in March 2018. Twenty-one of the stranded dolphins were returned alive to the sea, while 47 animals died. Dead dolphins included all ages, with more males than females (29 males and 18 females). The cause of death investigation reported here is restricted to 15 adult individuals and one fetus on which a full set of diagnostics was prioritized due to limited funding. Our results demonstrate that the death of 16 dolphins assessed in this study was not due to obvious human effects (e.g. bycatch) or underlying pathologies, as all animals were in good body condition and had no external evidence of injuries. Infections by Morbillivirus, Influenza A virus, Sarcocystis spp., Toxoplasma gondii, or Neospora caninum, as well domoic acid (DA) toxicity were ruled out as ethiologies in this event. Notably, results on exposure to paralytic shelfish toxins (PSP) were the only investigated cause of death found positive. This is the first documentation of exposure to PSP toxins in short-beaked common dolphins from the Argentine Sea. At present our results are insufficient to assess whether PSP toxin exposure played a role in the death of the stranded dolphins. Notwithstanding, the full documentation and investigation of the most commonly reported pathogens and toxins involved in cetacean mass strandings allowed us to clear the most relevant health differentials and suggests areas for future study. Additional potential hypothesis related to factors known or speculated to cause cetacean mass strandings are currently being explored within the ecological context at the time of the event.
... Apart from their role as zoonotic agents, parasites can also help in differentiating wild caught from legally bred imported R&A, based on the life cycle of the detected stages (Moré et al., 2013). ...
More than 100 amphibian and reptile species have established populations outside their natural geographical range, mostly as a consequence of the international pet trade. About 40 zoonoses are associated with reptiles and amphibians. The main zoonotic risks from alien invasive reptiles and amphibians are salmonellosis and probably also vibriosis from a bacteriological point of view, pentastomids, sparganosis and potentially trichinellosis from a parasitical point of view, and West Nile virus. There are also new and emerging pathogens, e.g. atypical Brucella spp., with zoonotic potential. Transmission of pathogens from introduced reptile and amphibian species to humans is limited by the important physiological differences between them and humans, the secretive or shy habits of most introduced species and the rarity of direct contact (with the notable exception of a few exotic species eaten by humans). Locally, alien reptiles include venomous species and large species able to inflict bites of medical concern. In certain areas some species (mainly anuran amphibians) are generating noise pollution affecting human well-being. Given the continued increase of invasive alien population establishments with time, the spread of alien arthropod vectors and aggravating factors such as climate change, it is expected that alien reptiles and amphibians and their associated pathogens will generate more public health concern in the future.
Citation: Pauwels, O.S.G. & Pantchev, N. 2018. Risks for human health related to invasive alien reptiles and amphibians. Pp. 108-119 in: Mazza, G. & Tricarico, E. (ed.). Invasive species and human health. Centre for Agriculture and Biosciences International, Wallingford: i-xxii + 1-186 pp.
... Apart from their role as zoonotic agents, parasites can also help in differentiating wild caught from legally bred imported R&A, based on the life cycle of the detected stages (Moré et al., 2013). ...
... Apart from their role as zoonotic agents, parasites can also help in differentiating wild caught from legally bred imported R&A, based on the life cycle of the detected stages (Moré et al., 2013). ...
... Our results on the prevalence of Sarcocystis infection among pythons and molecular characterization indicate that S. singaporensis is widely distributed in the Indo-Australian Archipelago [30], probably also being a frequent coccidian parasite of the green tree python (Morelia viridis) in New Guinea. Although our own molecular analysis of the samples from green tree pythons was still ongoing at the time of writing and could not be included here, More et al. [31] isolated an 18S rDNA sequence of Sarcocystis from this snake that showed 97% sequence identity with S. singaporensis. Whether or not S. singaporensis is also present in Australia could not be determined by our study, since molecular sampling did not yield a S. singaporensis-specific sequence despite sporocysts of appropriate size (class 1) being present. ...
... This is not surprising, since muscle cysts that resemble S. zamani have been described from potential intermediate hosts like Australian bush rats [34]. Furthermore, the recent publication of a Sarcocystis 18S rDNA sequence from sporocysts in green tree pythons (presumably of Papua New Guinean origin; [31]) that clustered with S. zamani in our phylogenetic analyses (Fig 1; KC201639) renders it plausible that S. zamani also occurs in New Guinea, linking Southeast Asia with Australia. A sequence variation of up to 2% divergence that was present among our samples of Sarcocystis sp.1 indicates a higher degree of variability than the variation observed among isolates of S. singaporensis throughout large parts of its distribution range. ...
We examined Sarcocystis spp. in giant snakes from the Indo-Australian Archipelago and Australia using a combination of morphological (size of sporocyst) and molecular analyses. We amplified by PCR nuclear 18S rDNA from single sporocysts in order to detect mixed infections and unequivocally assign the retrieved sequences to the corresponding parasite stage. Sarcocystis infection was generally high across the study area, with 78 (68%) of 115 examined pythons being infected by one or more Sarcocystis spp. Among 18 randomly chosen, sporocyst-positive samples (11 from Southeast Asia, 7 from Northern Australia) the only Sarcocystis species detected in Southeast Asian snakes was S. singaporensis (in reticulated pythons), which was absent from all Australian samples. We distinguished three different Sarcocystis spp. in the Australian sample set; two were excreted by scrub pythons and one by the spotted python. The sequence of the latter is an undescribed species phylogenetically related to S. lacertae. Of the two Sarcocystis species found in scrub pythons, one showed an 18S rRNA gene sequence similar to S. zamani, which is described from Australia for the first time. The second sequence was identical/similar to that of S. nesbitti, a known human pathogen that was held responsible for outbreaks of disease among tourists in Malaysia. The potential presence of S. nesbitti in Australia challenges the current hypothesis of a snake-primate life cycle, and would have implications for human health in the region. Further molecular and biological characterizations are required to confirm species identity and determine whether or not the Australian isolate has the same zoonotic potential as its Malaysian counterpart. Finally, the absence of S. nesbitti in samples from reticulated pythons (which were reported to be definitive hosts), coupled with our phylogenetic analyses, suggest that alternative snake hosts may be responsible for transmitting this parasite in Malaysia.
... Consensus sequences obtained were compared with others reported in GenBank by BLASTn analysis. Samples with inconclusive amplicon sequencing results were considered as potential mixed infections of different protozoan species [14]. Only assembled sequences with high quality chromatograms were submitted to GenBank (accessions numbers listed in Table 1). ...
... but also from other related coccidian. Therefore, samples that had shown inconclusive results in sequencing were considered as putative mixed infections [3,14,18]. Regarding species identification, only sequences with a BLASTn identity ≥ 99% were considered as species specific and the respective sequence entered into GenBank along with the respective species name. Sequences with lower identity with other reported sequences by BLAST as well as sequences that showed similar identity with more than one previously reported species were submitted to GenBank as 'Sarcocystis sp.'. ...
Sarcocystis spp. are obligatory intracellular protozoan parasites which can infect humans and animals. Most of Sarcocystis species were identified based on the detection of muscle cysts in different intermediate hosts (IH). Regarding to natural infection in definitive host, there are few reports which have reached to determining species of Sarcocystis. The present work was aimed to studying the occurrence of Sarcocystis spp. (oocysts and sporocysts) in mucosal scrapings of small intestine and fecal samples of one the most abundant wild canids from South America, Lycalopex gymnocercus (Pampas fox), and to identify the Sarcocystis spp. using molecular tools. A total of 131 free-living L. gymnocercus were sampled in rural areas located in several departments from Buenos Aires province, Argentina. Fecal samples from all the animals and 33 small intestines were analyzed. Fecal and mucosal scrapings samples were analyzed by sugar flotation method and once oocysts or sporocysts were detected, sedimentation was performed and DNA extracted with a commercial kit. A PCR was conducted using primers targeting a fragment of the 18S rRNA gene and the amplicons were purified and sequenced. Of the total Pampas foxes analyzed, 23 (17.6%) had Sarcocystis spp. oocysts/sporocysts in fecal and/or mucosal samples. Sarcocystis spp. sporocysts were detected in 13.0% (17/131) of fecal samples and in 39.4% (13/33) of mucosal samples by the initial sugar flotation. Twenty one L. gymnocercus samples were processed by DNA extraction and PCR. Molecular identification of Sarcocystis spp. infection was successfully achieved in 14 foxes and was distributed as follows: 4.6% S. cruzi (6/131), 3.8% Sarcocystis spp. using birds as IH (S. albifronsi and S. anasi among others, 5/131), 0.8% S. tenella (1/131) and 1.5% (2/131) with low homology (97%) with S. miescheriana. In one fecal sample with spherical oocysts, the sequencing results showed a 100% sequence identity with Hammondia heydorni. The results show that the mucosal scrapings are the eligible sample to identify prevalence and to proceed with species identification. Lycalopex gymnocercus is suggested as definitive host for S. cruzi, S. tenella and probably various Sarcocystis spp. using birds as intermediate hosts as well as for H. heydorni.
