Sarcocystis menglaensis n. sp. (Apicomplexa: Sarcocystidae) from Williamson's mouse deer Tuagulus williamsoni (Kloss) (Artiodactyla: Tragulidae).

Williamson's mouse deer, Tuagulus williamsoni (Kloss), is one of the smallest ungulates among tragulid species found in northern Thailand, and Yunnan Province, China. Here we describe Sarcocystis menglaensis n. sp., infecting two of 14 (14.3%) Williamson's mouse deer from south-western China. By light microscopy, sarcocysts of S. menglaensis are microscopic, up to 2,170 µm in length, and have a striated sarcocyst wall with 1.5-3.6 µm long palisade-like protrusions. Transmission electron microscopy observations revealed that sarcocyst wall is of "type 10f", and has numerous villar protrusions folded over the cyst wall. The villar protrusions contained microtubules dispersed throughout the protrusions. Phylogenetic analysis based on 18S rDNA and mitochondrial cox1 gene sequences indicated that S. menglaensis shared a close affinity with species of Sarcocystis Lankester, 1982 from ruminants, which utilise felids as definitive hosts.

[Association between polymorphisms of PSMB8, PSMB9 and TAP2 genes with rheumatoid arthritis in ethnic Han Chinese from Yunnan].

OBJECTIVE: To assess the association between single nucleotide polymorphisms (SNPs) of PSMB8, PSMB9 and TAP2 genes and rheumatoid arthritis (RA) in ethnic Han Chinese from Yunnan. METHODS: A case-control study was carried out using 177 RA patients and 288 healthy controls. Genotypes of rs2071543, rs55745125 and rs138635403 loci of PSMB8 gene, and rs17587 locus of PSMB9 gene were determined with polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). And a polymerase chain reaction amplification refractory mutation system (ARMS-PCR) was used for typing rs2228396 locus of TAP2 gene. Genotypic and allelic frequencies were calculated. An Epi Info 7 software was used to calculate the Odds Ratio (OR) of above SNPs between the two groups. RESULTS: Allelic and genotypic frequencies of rs138635403 and rs17587 loci have differed significantly between the two groups (P<0.05). The frequency of GG genotype for rs17587 locus was also higher in the RA group (0.672) compared with control group (0.524) (OR=1.862, 95%CI: 1.261-2.749). CONCLUSION: Genetic polymorphisms of rs17587 appeared to be associated with RA in ethnic Han Chinese from Yunnan.

Effects of frozen storage on the structure of sarcocysts in pig muscle and implications in taxonomic studies.

UNLABELLED: The morphology of the cyst wall of Sarcocystis has unique characteristics that can be used in species identification. To find a suitable way to preserve Sarcocystis cyst samples for species identification, by light microscopy and electron microscopy, we recorded the morphological changes in the cysts of Sarcocystis suihominis and Sarcocystis miescheriana from pig muscle, induced by storage at -20 degrees C. Comparisons were made between fresh cysts and those subjected to frozen storage for periods of 3 days, 20 days and 30 days. RESULTS: cyst wall of the two Sarcocystis species appeared unaffected by storage. There was no obvious change in the length, nor in the width of the protrusions after storage (P>0.05), but the structure of the bradyzoite in the sarcocyst was in many cases disintegrated at -20 degrees C in 20 days for S. miescheriana and 30 days for S. suihominis. To our knowledge this is the first report that Sarcocystis cyst in muscle can be stored at -20 degrees C before and remain suitable for ultrastructural morphological study. Consequently, this paper proposes freezing as a convenient storage method for samples used in taxonomic studies of Sarcocystis.

A taxonomic re-appraisal of Sarcocystis nesbitti (Protozoa: Sarcocystidae) from the monkey Macaca fascicularis in Yunnan, PR China.

The first detection of Sarcocystis nesbitti Mandour, 1969 in the Chinese mainland is reported and the morphology of the sarcocyst is described in detail. The parasite was detected in the monkey, Macaca fascicularis, maintained on a monkey farm in Yunnan Province; the infection may have occurred via faecal contamination from local rats, mice and/or birds. S. nesbitti was characterized as follows: a macroscopic sarcocyst, length of the cyst up to 2 mm; cyst wall smooth, thin and no perpendicular protrusion is seen under the light microscope; border of cyst wall wavy, primary cyst wall thin (38-65 nm) and invaginated; ground substance about 0.5-0.76 microm thick with electron-dense granules and concentric spherical bodies. The cyst wall is described as type 1 by electron microscopy. It is suspected that S. nesbitti may utilize Macaca mulatta, M. fascicularis, Cercocebus atys, and Papio papionis, as well as human as intermediate hosts. The taxonomy of S. nesbitti is re-appraised in the light of a consideration of possible experimental artefacts and examination of the past literature. Evidence is presented that S. nesbitti may be one of the species infecting humans in South Asia and that the monkey may be a potential reservoir host.

Characterization of Sarcocystis species in domestic animals using a PCR-RFLP analysis of variation in the 18S rRNA gene: a cost-effective and simple technique for routine species identification.

Thirteen restriction endonucleases were used to investigate nuclotide sequence variation in the 18S rRNA DNA of 88 individuals from ten Sarcocystis taxa collected as cysts from their intermediate hosts, swine, cattle and water buffalo. A DNA sequence of approximately 900 bp was used. A total of 26 electromorphs were detected. The electromorphs were sorted into seven different haplotypes that coincided with the six named species and an unidentified species from cattle. These findings support those of our morphological examinations, which suggested that the taxa resembling Sarcocystis hirsuta, S. hominis, both found in water buffalo, and S. sinensis found in cattle, are not new species but are in fact S. hirsuta and S. hominis as found in cattle, and S. sinensis as found in water buffalo; this finding supports the idea that these species can utilize both cattle and water buffalo as intermediate hosts and are not restricted to one or the other host group as previously thought. PCR-RFLP resolved by agarose gel electrophoresis is shown to be an easy and rapid method of discriminating between these species.