Study On Pathogen Identification Methods Of Sparganum Mansoni Infection Diagnosis

Objective:To observe and analysis the morphological characteristics of anatomy histology and tissue pathology of Sparganum mansoni (S.m) systematically for supplement the insufficient basic knowledge of the pathogen diagnosis. To study on the methods detecting specific antigens and genes in S.m sections in order to solve the technical problems of the parasite identification.Methods:Forty-two specimens of S. m from frogs and patients, thirteen specimens of other parasites and two human tissue specimens were collected to identify the pathogen. Various parts_and formalin-fixed and paraffin-embedded biopsy specimens of S. m were observed by the microscope morphologically and histologically. The serum of S.m immuned rabbit was prepared and was used to detect the specific antigen on biopsy tissue from difference parasite species with enzyme immuno-histochemistry method. Four pair of primers detecting S.m mtDNA COX1part gene fragment was designed. Genomic DNA was extracted from tissue sample with commercial kit. Target gene fragment was amplified by PCR. Target band was observed by electrophoresis and sequencing. The coincidence rate of the target gene sequence and known gene was obtained from blast sortware.Results:The anatomy histological structure of S.m showed that head suction slots with cystic cavity, the body wall with concave and convex cross folds, the reticular fiber structure in essence, rich in calcareous, visible discharge small tube in body posterior, a large number of round or oval shaped, the strong refraction disc body of the structure of the cell-free, calcareous, overflow from the parasites pierced can be seen. Individual of the calcareous is bigger than somatic cells in size. Histopathological characteristics of S.m show that head morphology is the most irregular, cross-section visible cavity and calcareous, that body and tail section is larger and there are differences in the organizational structure from different body section, except the head, that a common feature of the body wall in each section of the parasite shows bump-ranging cross folds, eosinophilic deeply stained cortical, microtriche visible in some parts of outside, no body cavity and digestive structure mesh loose in the parenchymal tissue with the dispersion of the muscle fibers and a circular, oval or irregularly shaped calcareous and also visible excretion lumen. Five of12pathological section from patients did not see the typical mesh structure (the calcification degeneration), calcareous and muscle fiber beam structure. The results of detection Paragonimus, cysticercus cellulosae of Taenia solium and S.mansoni with optimum condition enzyme immunohistochemical method did not show any false negative and false positive reaction. The positive reaction of detection the pathological slices from9patients with sparganosis were seen. Specific target band of S.mansoni in two pair (F650/R800and F965/R1120) of four pair of primers have was obtained by PCR amplification.Conclusion:The description of S.m anatomy histology and observing method for identification the pathogen prior to paraffin-embedded provides a simple means of pathology. Systematic observation and description on S.m histopathological features provided a reference for pathological diagnosis. The exploreation of the methods detecting S.m specific antigens and genes provides means for further suspected pathogen identification.