RESUMO
BACKGROUND: There has been considerable confusion concerning the number and classification of Sarcocystis spp. in chickens. Scarce nucleotide data of Sarcocystis spp. from chickens are provided in GenBank. The study aimed to investigate the morphological and molecular characteristics of Sarcocystis spp. found in chickens in China. METHODS: Tissues from 33 chickens were collected in 2019. Sarcocysts were observed using light (LM) and transmission electron microscopy (TEM). Individual sarcocysts from different chickens were selected for DNA extraction, and five loci, 18S rDNA, 28S rDNA, ITS1 region, the mitochondrial cox1 gene and the apicoplastic rpoB gene, were amplified from each sarcocyst, sequenced and analyzed. RESULTS: Only S. wenzeli was found in 14 of 33 (42.4%) chickens. Under LM, the sarcocysts were microscopic and exhibited palisade-like villar protrusions measuring 1.5-2.8 µm. Ultrastructurally, the sarcocyst wall contained numerous stubby hill-like villar protrusions. The protrusions included scattered microtubules, which extended from the tips of the protrusions into the ground substance. The five loci were successfully sequenced and the sequences deposited in GenBank. At 18S rDNA, ITS1 and cox1, the most similar sequences in GenBank were those of Sarcocystis sp. obtained from the brains of chickens, i.e. 99.9-100%, 98.1-98.5% and 99.3% identity, respectively. The five loci (18S rDNA, 28S rDNA, ITS1, cox1 and rpoB) showed different levels of interspecific sequence similarity with other closely related species of Sarcocystis (e.g. 99.8%, 99.0-99.2%, 89.3-89.7%, 98.5%, and 97.5%, respectively, with S. anasi). Phylogenetic analysis based on four of the loci (18S rDNA, cox1, rpoB and ITS1) revealed that S. wenzeli formed an independent clade with Sarcocystis spp. that utilize geese or ducks as intermediate hosts and canines as the known or presumed definitive host. CONCLUSIONS: To our knowledge, the sequences of 28S rDNA and rpoB reported here constitute the first records of genetic markers of Sarcocystis spp. in chickens. Based on molecular analysis, S. wenzeli might be responsible for the neurological disease in chickens, and ITS1 and rpoB are more suitable for discriminating it from closely related Sarcocystis spp. Phylogenetic analysis revealed that S. wenzeli presents a close relationship with Sarcocystis spp. in geese or ducks.
Assuntos
Galinhas/parasitologia , Sarcocystis , Sarcocistose/diagnóstico , Animais , Apicoplastos/genética , China/epidemiologia , DNA Ribossômico/genética , DNA Espaçador Ribossômico/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Genes Mitocondriais , Genes de Protozoários , Marcadores Genéticos , Microscopia Eletrônica de Transmissão , Patologia Molecular/métodos , Filogenia , Prevalência , Sarcocystis/classificação , Sarcocystis/genética , Sarcocystis/isolamento & purificação , Sarcocystis/ultraestrutura , Sarcocistose/veterináriaRESUMO
Three cyst-forming Sarcocystis species have been identified in horsemeat; however, there exists considerable confusion concerning their relationships. Here, 74% (34/46) of the examined tissue samples from horses contained sarcocysts based on examination by light microscopy (LM), and the organism was identified as Sarcocystis bertrami based on cyst structure. The S. bertrami cysts were microscopic (up to 6750 µm in length) and exhibited a striated wall with 2.0-5.1 µm villar protrusions (vps) under LM. Transmission electron microscopy (TEM) observations showed that the vps were tightly packed, similar to "type 11c". Four genetic markers (18S, 28S, ITS1 and the mitochondrial cox1 gene) of S. bertrami were sequenced and analyzed. The 28S and ITS1 sequences are the first records for Sarcocystis in horses. The newly obtained sequences of the 18S and cox1 genes both shared the highest similarities with those of S. bertrami and S. fayeri obtained from horses. Phylogenetic analysis based on the 18S, 28S and cox1 sequences revealed that S. bertrami and S. fayeri formed an independent clade within a group comprising Sarcocystis spp. from ruminants and pigs. Therefore, S. bertrami and S. fayeri are considered to represent the same species of Sarcocystis in horses, and S. fayeri is a junior synonym of Sarcocystis bertrami.
TITLE: Prévalence et caractéristiques morphologiques et moléculaires de Sarcocystis bertrami chez les chevaux en Chine. ABSTRACT: Trois espèces de Sarcocystis formant des kystes ont été identifiées dans la viande de cheval, mais il existe une confusion considérable concernant leurs relations. Ici, 74 % (34/46) des échantillons de tissus examinés provenant de chevaux contenaient des sarcocystes selon l'examen par microscopie optique (LM), et l'organisme a été identifié comme Sarcocystis bertrami selon la structure du kyste. Les kystes de S. bertrami étaient microscopiques (jusqu'à 6 750 µm de longueur) et présentaient une paroi striée avec des saillies villaires (vp) de 2,0 à 5,1 µm sous LM. Les observations en microscopie électronique à transmission ont montré que les vp étaient très serrées, similaires au « type 11c ¼. Quatre marqueurs génétiques (18S, 28S, ITS1 et le gène mitochondrial cox1) de S. bertrami ont été séquencés et analysés. Les séquences de 28S et ITS1 sont les premières de Sarcocystis chez les chevaux. Les séquences nouvellement obtenues de 18S et des gènes mitochondriaux cox1 partagent les similitudes les plus élevées avec celles de S. bertrami et S. fayeri obtenues à partir de chevaux. Une analyse phylogénétique basée sur les séquences de 18S, 28S et cox1 a révélé que S. bertrami et S. fayeri formaient un clade indépendant au sein d'un groupe comprenant les Sarcocystis spp. des ruminants et des porcs. Par conséquent, S. bertrami et S. fayeri sont considérés comme représentant la même espèce de Sarcocystis chez les chevaux, et S. fayeri est un synonyme plus récent de Sarcocystis bertrami.
Assuntos
Doenças dos Cavalos/epidemiologia , Sarcocystis/genética , Sarcocistose/veterinária , Animais , China/epidemiologia , DNA Ribossômico/genética , Genes Mitocondriais , Variação Genética , Doenças dos Cavalos/parasitologia , Cavalos/parasitologia , Filogenia , Prevalência , RNA Ribossômico 18S/genética , Sarcocystis/classificação , Sarcocistose/epidemiologiaRESUMO
In this study, 36.8% (28/76) of tissue samples collected from domestic pigs (Sus scrofa) contained sarcocysts, as determined by light microscopy. The organisms were identified as Sarcocystis miescheriana and Sarcocystis suihominis based on their morphological and molecular characteristics. Four genetic markers, i.e., 18S rDNA, 28S rDNA, ITS-1 region (ITS-1), and the mitochondrial COX1 gene (COX1), of the two parasites were sequenced and analyzed, and the 28S rDNA and ITS-1 of S. suihominis obtained from pigs constituted the first records of these markers in GenBank. The sequences of the four loci (18S rDNA, 28S rDNA, ITS-1, and COX1) of S. miescheriana shared high identities with those of S. miescheriana obtained from domestic and/or wild pigs in GenBank, with similarities of 99.6%, 99.6%, 95.9%, and 95.4%, respectively. The 18S rDNA sequences of S. suihominis exhibited 99.4% identity with those of S. suihominis from domestic and wild pigs. The comparison of the newly obtained sequences of the four genetic markers between the two parasites revealed that the interspecific similarities of 18S rDNA, 28S rDNA, ITS-1, and COX1 were 97.7%, 96.6%, 80.3%, and 81.2%, respectively. Therefore, the two species could be better discriminated with ITS-1 and mitochondrial COX1 compared with 18S rDNA or 28S rDNA. The phylogenetic analysis using 28S rDNA indicated that the two Sarcocystis species in domestic pigs had a close relationship.
Assuntos
Sarcocystis/crescimento & desenvolvimento , Sarcocystis/genética , Sarcocistose/veterinária , Doenças dos Suínos/parasitologia , Animais , China , DNA de Protozoário/genética , DNA Ribossômico/genética , Genes Mitocondriais , Filogenia , Reação em Cadeia da Polimerase , RNA Ribossômico 18S/genética , Sarcocystis/classificação , Sarcocystis/isolamento & purificação , Sarcocistose/parasitologia , Sus scrofa/parasitologia , SuínosRESUMO
The presence of Sarcocystis cysts in the muscle tissue of domestic dogs (Canis familiaris), which normally serve as definitive hosts, is unusual and infrequent. Here, S. caninum sarcocysts were identified for the first time in two of 37 dogs (2.7%) from China. Examination using light microscopy found that the S. caninum sarcocysts were up to 1520 µm long and up to 147 µm wide and contained numerous 1.5-3.3 µm wedge-like villar protrusions (vp). Transmission electron microscopy revealed that the sarcocysts had pleomorphic vp that closely resembled those of "type 9c." Five loci, 18S rDNA, 28S rDNA, mitochondrial cox1, ITS1 and ropB, were sequenced and characterized in S. caninum sarcocysts. The sequences of the five loci shared similarities of 99.9-100%, 99.0-100%, 99.4-100%, 99.6-100%, and 99.7-100%, respectively, with those of S. arctica. Phylogenetic analysis based on the sequences of 28S rDNA and mitochondrial cox1 indicated that S. caninum and S. arctica are closely related to Sarcocystis species that use a raptorial bird as their definitive host.
Assuntos
Doenças do Cão/parasitologia , Músculo Esquelético/parasitologia , Sarcocystis/genética , Sarcocystis/isolamento & purificação , Sarcocistose/veterinária , Animais , China , Ciclo-Oxigenase 1/genética , DNA Intergênico/genética , DNA Ribossômico/genética , Cães , Proteínas de Membrana/genética , Microscopia Eletrônica de Transmissão , Filogenia , Reação em Cadeia da Polimerase/veterinária , RNA Ribossômico 18S/genética , RNA Ribossômico 28S/genética , Sarcocystis/classificaçãoRESUMO
We report a draft sequence of the genome of Gordonia neofelifaecis NRRL B-59395, a cholesterol-degrading actinomycete isolated from fresh feces of a clouded leopard (Neofelis nebulosa). As predicted, the reported genome contains several gene clusters for cholesterol degradation. This is the second available genome sequence of the family Gordoniaceae.
