Ultrastructure and cytochemistry of intrauterine embryonic and larval stages of Ityogonimus lorum (Digenea: Brachylaimidae) involving transitory development of ciliated miracidia.

Results of the present study provide ultrastructural evidence that miracidial morphogenesis is fully completed within the intrauterine eggs while in the most posterior uterine regions of Ityogonimus lorum, a digenean parasite of an Iberian mole, Talpa occidentalis (Eulipotyphla, Talpidae). Using transmission electron microscopy (TEM), the ultrastructural characteristics of diverse cell types and their organelles of these developing embryos and fully formed miracidia within the eggshell were examined. The eggshell and embryonic envelopes are similar to those described previously by many authors for other digeneans. However, the developing miracidia are unique among previously described digeneans in possessing transitory cilia during larvigenesis, but completely lacking cilia in fully formed miracidium larvae. The evidence for completion of miracidial maturation in intrauterine eggs is based on the presence of the following structures: (1) transitional stage of ciliated differentiating miracidial epithelium; (2) apical and lateral glands, characteristic for digenean miracidia; and (3) fully developed germinative cells grouped together in the germinative sac localized in the posterior region of the miracidium. The protonephridial system with its characteristic flame cells and the nervous system with diverse types of neurons and nerve centers, which are characteristic for other digenean species reported until now, are absent from all these developmental stages of I. lorum. Based on these observations, we hypothesize that the life cycle of I. lorum is entirely terrestrial, involving passive transmission by ingestion of eggs containing unciliated miracidia to the first intermediate host.

Histopathological lesions in reproductive organs, distal spinal cord and peripheral nerves of horses naturally infected with Trypanosoma equiperdum.

BACKGROUND: Dourine, a venereal transmitted trypanosomosis caused by Trypanosoma equiperdum, has different clinical signs related to the reproductive and nervous system. Pathologic tissue changes associated with the disease are poorly described. The present study describes the histopathological lesions in naturally T. equiperdum-infected horses in the chronical stage of dourine. RESULTS: Four chronically dourine diseased horses underwent a post-mortem examination. They were Woo test negative, but CATT/T. evansi positive, had a low packed cell volume (PCV) and exhibited obvious clinical signs of dourine. Post-mortem examination did not reveal gross lesions in the organs assumed to be responsible for the symptomatology. On histopathology, genital organs were affected, with mononuclear cell infiltration and erosions and degeneration of seminiferous tubules and perivascular lymphoplasmacytic cuffing in the uterus. In the nervous system, mononuclear cell infiltration was located in peripheral nerves, ganglia and in the spinal cord, leading to axonal degeneration. Real-time PCR using ITS primer revealed the presence of trypanosomes in these organs and conventional PCRs using maxicircle and RoTat1.2 primers further confirmed the involvement of T. equiperdum since the DNAs from the vagina, testicle, distal spinal cord, sciatic and obturator nerves found to be positive for maxicircle and negative for RoTat 1.2. CONCLUSIONS: The histopathological lesions in the spinal cord and peripheral nerves explain the incoordination of the hind legs in T. equiperdum-infected horses, whilst its presence in the genital tract exemplifies the venereal transmission.

Bovine besnoitiosis in an endemically infected dairy cattle herd in Italy: serological and clinical observations, risk factors, and effects on reproductive and productive performances.

Bovine besnoitiosis (Besnoitia besnoiti) is an emerging parasitic disease of cattle in Europe. This study reports a case of bovine besnoitiosis in a dairy farm housing 217 cattle in Italy. A serological screening was performed on the whole herd using the recommended approach of ELISA and confirmatory Western Blot. Seropositive animals were clinically examined to reveal symptoms and lesions of besnoitiosis. Risk factors and the effects of the parasite infection on reproductive and productive performances were evaluated. Histopathology and molecular analyses on tissues from a slaughtered cow affected by the chronic phase of the disease were carried out. An overall seroprevalence of 23.5%, which increased up to 43.5% considering only cows, was recorded. Clinical examination of 33 of the seropositive cows evidenced the presence of tissue cysts in at least one of the typical localizations (sclera, vulva, or skin) in 25 animals. Statistical analysis did not evidence any significative impact of the parasite infection on herd efficiency; however, a decrease of productive parameters was recorded in cows showing cutaneous cysts. Concerning the chronically affected cow, histopathology revealed B. besnoiti tissue cysts in the skin of the neck, rump, hind legs, eyelid and vulva, in the muzzle, in mucosal membranes of the upper respiratory tract, and in the lungs. Parasite DNA was detected also in masseter muscles, tonsils, mediastinal lymph nodes, liver, cardiac muscle, aorta wall, ovaries, uterus, and vulva. Bovine besnoitiosis continues to spread in the Italian cattle population. Breeders and veterinarians should be aware of this parasitic disease, and control programs should be developed based on surveillance through a diagnostic procedure including both clinical examination and laboratory tests.

The first reported case of advanced aelurostrongylosis in Eurasian badger (Meles meles, L. 1758) in Bosnia and Herzegovina: histopathological and parasitological findings.

This paper represents the first description of advanced aelurostrongylosis in the Eurasian badger (Меles meles, L. 1758) from Bosnia and Herzegovina, which is an autochthonous species of the country. An adult female badger was found dead on a road; the cause of death was trauma but the emphasis in the paper is on severe verminous pneumonia caused by metastrongylids from genus Aelurostrongylus spp. This parasitological and histopathological finding confirms the presence of Aelurostrongylus in mustelids in Bosnia and Herzegovina and the Balkans.

Extraintestinal oxyuriasis - report of three cases and review of literature.

Extraintestinal oxyuriasis, in our experience with three affected women of fertile age, presented itself as a solitary fibrotic nodular lesion, with a varying location. The sites of location were: parietal peritoneum, serous surface of the uterus and wall of the uterine tube. The size of the nodules was 5 to 10 mm. Histologically, the lesions were hypocellular fibrotic nodules with a variable amount of neutrophils and amorphous eosinophilic material in the center, harbouring eggs of the parasite and remnants of pinworm cuticle. All three lesions were asymptomatic, only being discovered incidentally during the operations for unrelated conditions. Their peroperative recovery by a surgeon did not alter the course of surgery. These findings document the ability of pinworms to migrate into the abdominal cavity via the female genital tract.

Early intrauterine embryonic development in Khawia sinensis Hsü, 1935 (Cestoda, Caryophyllidea, Lytocestidae), an invasive tapeworm of carp (Cyprinus carpio): an ultrastructural study.

Intrauterine embryonic development in the caryophyllidean tapeworm Khawia sinensis has been investigated using transmission electron microscopy and cytochemical staining with periodic acid-thiosemicarbazide-silver proteinate for glycogen. Contrary to previous light microscopy findings that reported the release of non-embryonated eggs of K. sinenesis to the external environment, the present study documents various stages of embryonation (ovoviviparity) within the intrauterine eggs of this cestode. At the initial stage of embryonic development, each fertilised oocyte is accompanied by several vitellocytes that become enclosed within the operculate, electrondense shell. Cleavage divisions result in formation of blastomeres (up to about 24 cells) of various sizes. Mitotic divisions and apparent rosette arrangment of the blastomeres, the latter atypical within the Eucestoda, are observed for the first time in the intrauterine eggs of K. sinenesis. The early embryo enclosed within the electrondense shell is surrounded by a thin membraneous layer which in some enlarged regions shows presence of nuclei. Simultaneously to multiplication and differentiation, some of the blastomeres undergo deterioration. A progressive degeneration of the vitellocytes within eggs provides nutritive reserves, including lipids, for the developing embryo. The possible significance of this atypical timing of the intrauterine embryonic development to (1) the ecology of K. sinensis and that of a recent introduction of another invasive tapeworm, the caryophyllidean Atractolytocestus huronensis Anthony, 1958 to Europe; and (2) the affiliation of caryophyllideans with other lower cestodes, are discussed.

The effects of interleukin (IL)-12 and IL-4 deficiency on worm development and granuloma formation in Schistosoma japonicum-infected mice.

CD4(+) T-helper (Th) cell is widely recognized to be capable of influencing worm development and egg granuloma formation after schistosome infection. Interleukin (IL)-12 and IL-4 play key roles in regulation of Th cell differentiation. In the present study, we subcutaneously inoculated mice with hybridoma cells secreting monoclonal antibodies to neutralize IL-12 and IL-4 and explored the effects of IL-12 and IL-4 deficiency on the worm development and granuloma formation in mice infected with cercariae of Schistosoma japonicum. It was found that deficiency of host IL-12 and IL-4 supported normal parasite survival and fecundity. However, worm development (length and female fecundity) was significantly enhanced in anti-IL-12-treated mice. Mean length of worms in anti-IL-12-treated group was significantly greater than that of intact controls on day 28 after infection (females, 11.84 ± 1.20 mm vs. 9.45 ± 1.34; males, 9.35 ± 1.21 mm vs. 8.10 ± 0.85 mm, p < 0.05). Liver egg load per pair of worms (1,770.12 ± 470.67 vs. 806.08 ± 232.37, p < 0.05) and uterine egg load of ovigerous females (93.08 ± 27.85 vs. 46.05 ± 34.24, p < 0.05) in anti-IL-12-treated mice were significantly higher than those in intact control 28 days postinfection. But these effects diminished 42 days postinfection (p > 0.05). Granuloma size in anti-IL-12-treated mice was significantly larger than that in intact mice 42 days postinfection (398.3 ± 80.7 µm vs. 294.4 ± 72.2 µm, p < 0.05). Granuloma fibrosis dramatically intensified in anti-IL-12-treated mice but diminished in anti-IL-4-treated mice. The results suggest that IL-12 may play an impeditive role in the development of S. japonicum and in granuloma formation as well as fibrosis. IL-4 may promote granuloma formation but have no effect on worm development.

Characterization and vaccination of two novel Schistosoma japonicum genes screened from a cercaria cDNA library.

Two novel genes, SJCWL05 and SJCWL06, were harvested from screening of Schistosoma japonicum (S. japonicum) cercaria cDNA library by using pig sera vaccinated (VPS) with S. japonicum immature egg ws-vaccine (S. japonicum iEw). Prokaryotic recombinant plasmids pGEX-4T-1/SJCWL05 and pGEX-4T-1/SJCWL06 were constructed to analyze their immunogenicity, which was confirmed by SDS-PAGE and Western blotting. Two eukaryotic recombinant plasmids, pcDNA3/SJCWL05 and pcDNA3/SJCWL06, were constructed, and their ability to protect mice against challenge of S. japonicum was evaluated. All mice vaccinated with pcDNA3/SJCWL05 or pcDNA3/SJCWL06 developed ELISA-specific anti-S. japonicum SIEA (S. japonicum soluble immature egg antigens) antibody. Immunoprotection experiments showed that worms and liver eggs reduced 34.64% and 39.14% in the pcDNA3/SJCWL05 group and those reduced 27.17% and 27.95% in the pcDNA3/SJCWL06 group, respectively. The reduction rates of intestine and uterine eggs in female worms of both groups reached 39.45% and 38.5% as well as 30.02% and 28.7%, respectively. Results of our study suggest that novel genes, SJCWL05 and SJCWL06, are potential vaccine candidates against schistosomiasis japonica.

Co-infection with Toxoplasma gondii and Clostridium perfringens in a postpartum woman with uterine gas gangrene: a case report.

Toxoplasmosis is a protozoan infection caused by Toxoplasma gondii. We report a case of Toxoplasma gondii and Clostridium perfringens co-infection complicating uterine gas gangrene following a term pregnancy. The histological examination of the necrotic uterine tissues and uterine swab cultures obtained at laparotomy revealed T. gondii and C. perfringens, respectively. Treatment was administered with bactericidal activity against both pathogens and the patient had an uneventful post-operative recovery. Although there have been some cases that have documented an association between toxoplasmosis and non-uterine C. perfringens infection, such a relationship has not been established. It is of interest to determine if the presence of both organisms can explain the severe myonecrosis that occurs in some cases of uterine gas gangrene.

A new gonad-infecting species of Philometra Costa, 1845 (Nematoda: Philometridae) from the marine fish Terapon jarbua (Forsskål) (Terapontidae) off the eastern coast of India.

A new nematode species, Philometra terapontis n. sp. (Philometridae), is described from male and female specimens found in the ovary of the jarbua terapon Terapon jarbua (Forsskål) (Terapontidae, Perciformes) from the Bay of Bengal off the eastern coast of India. Based on light and scanning electron microscopical examination, the new species differs from most other gonad-infecting Philometra spp. in the length of the spicules (105-114 µm), a gubernaculum with dorsal, lamella-like structures and a distinct protuberance on its distal end, and a U-shaped, dorsally uninterrupted caudal mound in the male. From a few congeneric, gonad-infecting species with unknown males, it can be distinguished by morphological and biometrical features found in gravid females (i.e. length of body, length of first-stage larvae or oesophagus, and caudal structure), by the host type (fish family) and by the geographical distribution. Philometra terapontis is the first philometrid species reported from a fish belonging to the family Terapontidae. Philometra sawara Quiazon, Yoshinaga & Ogawa, 2008 is considered a junior synonym of P. scomberomori (Yamaguti, 1935). A key to gonad-infecting species of Philometra parasitising marine and brackish-water fishes is provided.

Early onset of clinical leishmaniosis in a litter of pups with evidence of in utero transmission.

BACKGROUND: Canine leishmaniosis (CanL) is a zoonotic disease caused by Leishmania infantum. Although usually transmitted by phlebotomine sand flies, infection by vertical transmission and by blood transfusion have also been reported. METHODS: We describe the very early onset of clinical leishmaniosis, starting from 2 months of age, in a litter of pups born to an infected dam and sire. Seven pups from the litter of nine living in different households showed alopecic, exfoliative dermatitis and ulcerative cutaneous lesions. All pups and both parents were tested on at least one occasion both serologically, by enzyme-linked immunosorbent assay (ELISA), and by polymerase chain reaction (PCR) targeting the Leishmania ribosomal operon internal transcribed spacer 1 region and a short fragment of the kinetoplast minicircle; positive amplicons were sequenced. RESULTS: All nine pups were PCR positive for L. infantum verified by DNA sequencing, seven were positive by conjunctival, five by blood, four by lymph node, and one by skin PCR from an ulcerative lesion. Both pups with no clinical signs were seronegative, while five of the seven pups with dermatologic abnormalities were seropositive by ELISA. The sire had typical clinical dermatologic and visceral findings of CanL, was seropositive and PCR positive for L. infantum in the lymph node and fluid from the vas deferens tested after the testes were removed by castration. The dam was sub-clinically infected and seronegative, but positive by blood, lymph node and conjunctival PCR for L. infantum. Allopurinol administered to all clinically affected dogs resulted in clinical recovery. CONCLUSIONS: Infection with L. infantum in both parents, the very early age of clinical onset among most of the pups, and the fact that the puppies were born and detected with signs of leishmaniosis in the winter, which is a season without sand fly activity in Israel, strongly suggest vertical transmission. Awareness of the possibility of vertical transmission of L. infantum and infection in littermates should be increased. It is recommended that littermates of young dogs with clinical leishmaniosis should be tested for sub-clinical infection as they may also be infectious to sand flies and thus to other dogs and to humans. Restricting the mating of infected bitches should also be considered to prevent the vertical transmission of the infection.

Schistosoma japonicum: screening of cercariae cDNA library by specific single-chain antibody against SIEA26-28 ku and immunization experiment of the recombinant plasmids containing the selected genes.

To obtain the gene encoding SIEA26-28 ku, which has been proven to be a potential anti-schistosomiasis vaccine candidate, screening Schistosoma japonicum (Sj) cercariae cDNA library with soluble specific single-chain antibody (SIEA26-28 ku-scFv) was performed. A large amount of specific single-chain antibody was harvested through construction of recombinant expression vector pET32a/scFv. The protein was purified and characterized. By using this protein (PET32a-scFv) as a probe, S. japonicum cercariae cDNA library was screened. Two strong positive clones were selected, and their eukaryotic recombinant plasmids were constructed. These genes were named as S. japonicum ribosomal protein S4 (SjRPS4) and S. japonicum ribosomal protein L7 (SjRPL7), respectively. Experiments of mice showed that both SjRPS4 and SjRPL7 DNA vaccines could induce significant immunoprotection. Result of these experiments further proved that the specific single-chain antibody is a very valuable tool in screening of cDNA library to get the corresponding molecules.

A new species of Calicotyle Diesing, 1850 (Monogenea: Monocotylidae) from the shortspine spurdog Squalus mitsukurii Jordan & Snyder and the synonymy of Gymnocalicotyle Nybelin, 1941 with this genus.

Calicotyle japonica n. sp., collected from the uterus, rectal gland, archinephric duct and cloaca of the shortspine spurdog Squalus mitsukurii Jordan & Snyder (Squaliformes) off the Pacific coast of Japan, is described. The new species can be distinguished from C. inermis Woolcock, 1936 by the shape of the male copulatory organ; in C. japonica this is directed anteriorly, is sharply bent in the middle and then increases in width toward the tip, whereas it is long, coiled and uniform in width throughout its entire length in C. inermis. Furthermore, the intestinal caeca have many irregular diverticula on both sides and the vaginal apertures are at the level of the common genital pore in C. japonica, whereas in C. inermis the intestine is smooth and the vaginae open at the level of the oötype. A phylogeny constructed using LSU rDNA data indicates that the new species is grouped with other Calicotyle species; based on this, Gymnocalicotyle Nybelin, 1941 is synonymised with Calicotyle Diesing, 1850. Calicotyle is divided into two major clades, with the new species being grouped with Calicotyle species infecting sharks and the second clade consisting of Calicotyle spp. infecting rays. This suggests that the loss of the hamuli in C. japonica and C. inermis, both parasites of sharks, is a comparatively recent event in the evolution of the genus.

Enterobius vermicularis infestation of a hysterectomy specimen in a patient with a colonic reservoir.

A 43-year-old woman (gravida 2, para 1011) with a history of uterine leiomyomata and a Barnett colonic reservoir underwent a supracervical hysterectomy. Final pathology revealed Enterobius vermicularis within the myometrium and adnexal vasculature. Infection may have occurred through a modified mode given the presence of a Barnett colonic reservoir and absence of an anus.

Plasmodium falciparum exposure in utero, maternal age and parity influence the innate activation of foetal antigen presenting cells.

BACKGROUND: Malaria in pregnancy is associated with immunological abnormalities in the newborns, such as hampered T-helper 1 responses and increased T-regulatory responses, while the effect of maternal Plasmodium falciparum infection on foetal innate immunity is still controversial. MATERIALS AND METHODS: The immunophenotype and cytokine release by dendritic cells (DC) and monocytes were evaluated in cord blood from 59 Beninese women with or without malaria infection by using flow cytometry. RESULTS: Accumulation of malaria pigment in placenta was associated with a partial maturation of cord blood myeloid and plasmacytoid DC, as reflected by an up-regulated expression of the major histocompatibility complex class II molecules, but not CD86 molecules. Cells of newborns of mothers with malaria pigment in their placenta also exhibited significantly increased cytokine responses upon TLR9 stimulation. In addition, maternal age and parity influenced the absolute numbers and activation status of cord blood antigen-presenting cells. Lastly, maternal age, but not parity, influenced TLR3, 4 and 9 responses in cord blood cells. DISCUSSION: Our findings support the view that placental parasitization, as indicated by the presence of malaria pigment in placental leukocytes, is significantly associated with partial maturation of different DC subsets and also to slightly increased responses to TLR9 ligand in cord blood. Additionally, other factors, such as maternal age and parity should be taken into consideration when analysing foetal/neonatal innate immune responses. CONCLUSION: These data advocate a possible mechanism by which PAM may modulate foetal/neonatal innate immunity.

Evaluation of Toxoplasma gondii placental transmission in BALB/c mice model.

Toxoplasma gondii infection is common worldwide and highly important to pregnant women as it can be transmitted to the fetus via the placenta. This study aimed at evaluating the prevention of placental transmission in two different strains after chronic infection with each one of the strains. A BALB/c mice model was inoculated 30days before breeding (immunization) and re-infected 12 and 15days after pregnancy (challenge). Seven experimental groups were assayed: G1: ME49-immunization (type II), M7741-challenge (type III); G2: M7741-immunization, ME49-challenge; G3, ME49-immunization; G4: M7741-immunization; G5: ME49-challenge; G6: M7741-challenge; G7: saline solution inoculation. Serology, mouse bioassay, PCR and RLFP of the uterus, placenta and fetus were performed to determine the congenital transmission of the strains challenged after chronic infection. IgG T. gondii antibodies were detected in G1, G2, G3 and G4, but not in G5, G6 and G7. All animals of G5 and G6 were IgM-positive. Congenital infection was not detected by bioassay and PCR. Nonetheless, placentas from G3 and G4 resulted positive but no corresponding fetal infection was detected. G1 and G2 did not show the genotype of the strain challenged during pregnancy, only those of chronic infection. Thus, the chronically infected BALB/c mice showed no re-infection after inoculation with another strain during pregnancy. Further studies with different parasite loads and different mice lineages are needed.

A Rare Case of Secondary Hydatid Cyst: Uterus and Colon Locations in the Same Patient

The aim of the present study was to present a case with secondary hydatid cysts in both uterus and colon. The patient was a 71-year-old female living in Hakkari, Turkey. She was admitted to the Van Yuzuncu Yil University Faculty of Medicine Medical Center with complaints of chronic abdominal and pelvic pain, and swelling in the abdomen. First, the sagittal T2 weighted magnetic rezonance imaging (MR) showed a type-3 cyst hydatid with daughter vesicles located at the posterior of uterus. Later, MR revealed a type-2 cystic lesion with detached membrane adhered to the anterior wall of colon and it was reported to be associated with abdomen. When the previous liver surgery history of the patient was kept in mind, the new finding was suggestive of a secondary cystic hydatid . In conclusion, it is possible to diagnose secondary cystic echinococcosis in patients with a history of primary cyst surgery in liver or any other organ by combining the symptoms and imaging findings.

Comparative histopathology and antibody responses of non-Tritrichomonas foetus trichomonad and Tritrichomonas foetus genital infections in virgin heifers.

The potential pathogenicity of non-Tritrichomonas foetus trichomonads (NTfTs) recently isolated from the prepuce of virgin bulls is not known. The purpose of this study was to determine the ability of these NTfTs to cause disease in the female reproductive tract relative to T. foetus. Forty-four virgin heifers were experimentally infected intravaginally with either one of two NTfTs (Pentatrichomonas hominis or Tetratrichomonas spp.), T. foetus, or sterile media and cultured weekly from 0 time until slaughter at 8 weeks. Serum and vaginal antibody responses during infection were assessed, and the reproductive tracts were histologically examined, scored, and compared based on numbers of neutrophils, eosinophils, lymphocytes, and plasma cells as well as the qualitative appearance of the reproductive tract. The NTfTs did not persist in the reproductive tract, while T. foetus persisted for at least 6-8 weeks. Further, no vaginal IgA response to infection was found in NTfT-infected and control heifers, but a vaginal IgA response was present in the T. foetus-infected group. Heifers infected with NTfT or controls showed little mucosal inflammatory response compared to T. foetus-infected heifers. Among the trichomonads studied, persistent infection by T. foetus alone seems responsible for uterine inflammatory lesions usually associated with pregnancy loss. The NTfTs studied in this work only transiently infected the vagina and were associated with strictly mild inflammatory changes, which probably do not cause significant disease, i.e., pregnancy loss.

Histological and lectin binding changes in the genital tract of mice infected with Tritrichomonas foetus.

An experimental murine model of bovine genital tritrichomonosis is described. Female mice were inoculated per vaginam with Tritrichomonas foetus and a sample of the study population was killed every 3 days up to 60 days post-infection. Microscopical changes in the reproductive organs were assessed and immunohistochemistry was used to detect T. foetus within these tissues. Lectin histochemistry was used to determine changes in the expression of carbohydrates within the reproductive mucosa. A range of microscopical changes were detected in the uterine endometrium by 10 days post-inoculation and these were associated with the presence of the protozoan. The endometrial changes included endometritis and ulceration, mucosal atrophy and glandular metaplasia, and were similar to those reported in naturally infected cows. Changes in lectin binding were recognized first in the vagina where there was increased binding of Ulex europaeus agglutinin-1 (UEA-1) which was maximal on day 16 post-inoculation. Within the uterus, there was increased binding of soy bean agglutinin (SBA) which was maximal on day 19 post-inoculation, and of peanut agglutinin (PNA) which was maximal on day 16 post-inoculation. These changes in carbohydrate expression parallel the infection kinetics, since they appeared first in the vagina and later in the uterus. The changes may reflect either a host reaction against the infection or the production of enzymes by T. foetus, which act to enhance adhesion and colonization of the genital organs by the organism. The kinetics and pathogenesis of this murine infection are similar to those of the natural bovine disease, suggesting that this model system may be valuable for further studies of this disease.

[Anti-fecundity effect of soluble immature egg antigen of Schistosoma japonicum in mice].

OBJECTIVE: To study anti-female fecundity effect in mice immunized with soluble immature egg antigen (SIEA) of Schistosoma japonicum, and observe possible mechanism. METHODS: Immature eggs were collected from the liver of a rabbit 34 days after being infected with 3000 cercariae of S. japonicum, and soluble antigen was prepared routinely. 20 ICR mice were divided randomly to 2 groups. 11 mice were immunized with SIEA (100 microg per mouse) and Freund adjuvant and the other 9 were injected with equal volume of sterile normal saline and Freund adjuvant as control. All mice received injection 5 times in 2 weeks interval. One week following the last vaccination, mice were challenged with 30 +/- 2 cercariae of S. japonicum Yunnan isolate. Feces were collected on day 45. All mice were sacrificed on day 46. The number of worms collected, number of eggs in feces, female uterus and liver, and the number of egg granulomas on the liver surface were compared between the 2 groups. The vitelline gland of female and testes of male worms were examined by transmission electron microscopy. RESULTS: There was no significant difference on the worm number between the immunized group and control (P > 0.05). The eggs per gram feces and liver, eggs in uterus per female, and egg granulomas on the liver surface were (56.68 +/- 24.78), (5 826 +/- 437), (49.94 +/- 12.53) and (10.04 +/- 1.13)/0.25 cm2, respectively in immunized group, while in control group these were (89.93 +/- 32.18), (10016 +/- 3541), (76.54 +/- 19.77) and (19.22 +/- 2.45)/0.25 cm2 respectively, all with significant difference (P < 0.05). Ultrastructure of the reproductive organs of paired adult worms showed that mature vitelline cells and lipid droplets in the cytoplasm of the cells decreased in the vitelline glands of immunized mice. More sustentacular cells and fewer spermatids were seen in testes of immunized mice. Vacuoles were seen in the cytoplasm of vitelline cells and sustentacular cells. CONCLUSION: The results indicated that SIEA may have an anti-fecundity effect possibly through inhibiting the maturation of germinal cells.