[Establishment of an animal model of Sparganum mansoni infection and study on therapeutic methods II Establishment of a mouse model of sparganosis mansoni via oral administration of procercoids].

OBJECTIVE: To establish an animal model of sparganosis mansoni through oral administration of Cyclops infected with procercoids. METHODS: Domestic cats were infected with Sparganum mansoni under laboratory conditions, and fresh cat stool samples were collected, washed in dechlorinated water, and filtered. Spirometra mansoni eggs were collected and prepared into suspensions. Twenty C57BL/6j mice were randomly divided into the experimental group (n = 15) and the control group (n = 5). Wild Cyclops were infected with Spirometra mansoni coracidia to allow 3 to 5 procercoids in each Cyclop. Then, each mouse in the experimental group was given 15 Cyclops infected with procercoids by gavage, while mice in the control group were orally administered with the same volume of dechlorinated water. All mice were sacrificed after 5 months, and dissected, and suspicious Sparganum mansoni worms were collected. The serum specific IgG antibody against Sparganum mansoni was measured in mice using enzyme-linked immunosorbent assay (ELISA). Genomic DNA was isolated from suspicious Sparganum mansoni worms, and the specific Sparganum mansoni cytochrome oxidase I (COI) gene was amplified using PCR assay. RESULTS: Among the 15 mice in the experimental group, six were positive for the serum specific IgG antibody against Sparganum mansoni, and milky white worms were found and collected from the subcutaneous regions of 4 out of 6 mice. Only one worm was detected in each mouse, and the worm morphology was similar to Sparganum mansoni. Capillary electrophoresis of the PCR amplification products of COI gene presented a specific band with 151 bp in size, and sequencing analysis revealed 100% homology with Sparganum mansoni. CONCLUSIONS: A mouse model of sparganosis mansoni is successfully created through oral administration of Cyclops infected with Spirometra mansoni procercoids.

[Prevalence of Spirometra mansoni infections in hosts in Jiangsu Province].

OBJECTIVE: To investigate the prevalence of Spirometra mansoni infections in hosts in Jiangsu Province, so as to provide the scientific basis for the management of sparganosis mansoni. METHODS: From 2018 to 2019, nine counties (cities, districts) were randomly selected from Jiangsu Province as the survey sites, and 100 healthy individuals were randomly selected to perform the serological test of S. mansoni infections and the detection of S. mansoni eggs. The procercoids were detected in the intermediate host Cyclops, and the S. mansoni eggs were identified in the stool samples of the definitive hosts cats and dogs. RESULTS: The prevalence of S. mansoni human infections was 0 (0/900) in the 9 survey sites of Jiangsu Province, and the sero-prevalence of the specific IgG antibody against S. mansoni was 1.22% (11/900). The positive rate of procercoids was 0.33% (3/900) in Cyclops. In addition, the S. mansoni egg-positive rate was 1.48% (2/135) in cats and dogs. CONCLUSIONS: Sparganosis mansoni is prevalent in Jiangsu Province. Health education pertaining to the damages of sparganosis mansoni and the route of S. mansoni infections should be improved.

Effect of gossypol on the potential difference of rat seminiferous tubules.

The p.d. of the rat seminiferous tubules was 4.75 +/- 1.39 mV (lumen negative) at 35 degrees C and varied linearly with temperatures from 26 to 40 degrees C. A depolarization of the seminiferous tubules was found in the rats administered with gossypol at the dosage of 30 mg/kg body weight for 3 weeks, the p.d. lowered to 3.63 +/- 0.79 mV at 35 degrees C and was independent of the changes of seminiferous tubules temperature. In the 5-week-gossypol-treatment group, the tracer penetrated not only the myoid cell layer, but also went beyond the tight junction complexes between Sertoli cells. The lanthanum appeared in the cleft surrounding spermatogonia. In the 8-week-gossypol-treatment group, the lanthanum was found in the adluminal compartment. It indicates that gossypol can cause a dysfunction of the Sertoli cells and blood-testis barrier and disturb a good physiological environment for the developing spermatocytes.