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1.
The importance of preparation technique, culture media and incubation time in the embryonation of the infective egg stages of the intestinal nematode parasite Heterakis gallinarum was studied. Mature H. gallinarum worms were isolated from the caeca of infected chickens and separated by sex. In a first experiment intact female worms were kept for the development of their eggs in four different media (0.5% formalin, 2% formalin, 0.1 N sulphuric acid, 0.1% potassium dichromate) and incubated under constant temperature (20-22 degrees C) for 2, 4, 6 or 8 weeks. Afterwards the body of the worms were ruptured and the numbers of unembryonated and embryonated eggs were determined using a McMaster egg counting chamber, and the percentage of embryonated eggs was calculated. After 8 weeks of incubation in 0.5% formalin, 0.1 N sulphuric acid or 0.1% potassium dichromate 27.6%, 26.7% and 29.4% of the eggs, respectively, embryonated into third stage larvae (p > 0.05). In contrast, incubation in 2% formalin resulted in an embryonation of 18.6% only (p < 0.05). In a second experiment H. gallinarum eggs were directly harvested from worm uteri and cultivated afterwards in different media (2% formalin, 0.1 N sulphuric acid, 0.1% potassium dichromate) at 20 to 22 degrees C for 6 weeks. An incubation of isolated eggs in 2.0% formalin or 0.1% potassium dichromate during 6 weeks resulted in a significantly higher percentage of embryonation in comparison to the incubation of intact worms (first experiment). The results suggest that preparation technique, media and time of incubation has an essential influence on the development rate of H. gallinarum eggs. 相似文献
2.
Three experimental infections of weaning pigs with 2000 embryonated Ascaris suum eggs each, 11 days apart, followed each time by fenbendazole treatment, produced a significant host response when compared with similar infected or uninfected control pigs as assessed by response to a subsequent challenge with 100 embryonated A. suum eggs. The response elicited from pigs treated with fenbendazole on either 2, 3, and 4 days or, 6, 7, and 8 days after each experimental infection was expressed as a reduction in the number of pigs with A. suum, in the number of worms per pig, in the weight of male and female worms, and in the length of male and female worms. No differences in average daily weight gain, feed-conversion efficiency or histology of lungs and liver were noted among the 4 treatment groups. 相似文献
3.
High hydrostatic pressure processing (HPP) is an effective non-thermal treatment used to inactivate pathogens from a variety of food and food products. It has been extensively examined using prokaryotic organisms and protozoan's but has had limited study on metazoans. Treatment using HPP has been shown to be effective in inactivating nematode larvae in food and preventing embryonation of Ascaris suum eggs. We conducted experiments using eggs of the canine whipworm Trichuris vulpis collected from naturally infected dogs and A. suum eggs from naturally infected pigs. We observed a delay in development of eggs of T. vulpis in a preliminary experiment and conducted 2 experiments to test the hypothesis that appropriate HPP levels can induce a delay in embryonation of nematode eggs. In experiment 1, nonembryonated T. vulpis eggs in tap water were packaged in sealable bags and exposed to 138-600 megapascals (MPa; 1 MPa=10 atm=147 psi) for 60s in a commercial HPP unit. In a second experiment, nonembryonated eggs of A. suum were exposed to 138-600 MPa and treated for 60s in the same commercial HPP unit. Embyronation of T. vulpis eggs was delayed by 4 and 5 days for eggs treated with 207 and 241 MPa but eventually eggs developed and the numbers of embryonated eggs was similar to controls on day 55. Embryonation of T. vulpis eggs treated with 345 or 350 MPa was delayed by 9 days and never reached more than 5% of eggs embryonated. On day 55 post treatment, 95% of control nontreated T. vulpis eggs were embryonated, 100-65% of eggs treated with 138-276 MPa were embryonated, a maximum of 5% of eggs treated with 345-350 MPa were embryonated, and 0% of eggs treated with ≥ 400 MPa were embryonated. T. vulpis eggs treated with ≥ 400 MPa did not undergo cell division. Embryrnation of A. suum eggs was delayed by 4, 10, and 16 days for eggs treated with 207, 241, and 250MPa, respectively, compared to nontreated control eggs. A. suum eggs treated with 207 MPa eventually embryonated to similar % embryonation values as controls and 138 MPa treated eggs but eggs treated with 241 or 250 MPa were always <5% embryonated. A. suum eggs treated with ≥ 300 MPa did not undergo cell division. On the final day of examination at day 56 after treatment, the % of embryonated eggs was 92% nontreated controls, 94% treated with 138 MPa, 84% treated with 207 MPa, 2% treated with 241 or 250 MPa, and 0% treated with 276, 200, 345, 400, or 414 MPa, respectively. 相似文献
4.
Immunity of swine to Ascaris suum 总被引：1，自引：0，他引：1
Swine were hyperimmunized to Ascaris suum by giving multiple oral inoculations of embryonated eggs. Sera and lymphocyte lysate from these pigs were administered parenterally to 4-week-old pigs. The latter animals were no more resistant to larval migration than control pigs receiving sera or lymphocyte lysate from non-immunized pigs. Other pigs were infected with transmissible gastroenteritis (TGE) virus, allowed to recover and challenged with embryonated ascarid eggs. They likewise were no more resistant to ascarid larval migration than control pigs. 相似文献
5.
The study investigated the effect of gastrointestinal passage in pigs on free-living stages of bovine nematodes. Two Landrace x Yorkshire pigs, A and B, were fed fresh eggs of Ostertagia ostertagi and Cooperia oncophora while two other pigs, C and D, were fed third stage larvae (L3) of the same parasites. Faeces from the pigs were collected for 48 h after ingestion. In pigs A and B, 15 and 66% of the eggs were recovered after passage, respectively. However, only 0.003 and 0.002% of the ingested eggs developed into third stage larvae (L3) after subsequent culturing. In pigs C and D, 0.01 and 0.02% of the L3 survived the passage of the gastrointestinal tract. Fresh O. ostertagi and C. oncophora eggs were cultured in parasite free porcine and bovine faeces. Only 0.05% L3 developed in porcine faeces, whereas 21% of the eggs developed into L3 in the bovine culture. Our results demonstrate an extremely poor rate of development and survival of both bovine nematode eggs and infective larvae after passage in pigs. It may imply that pigs can play an important role in reducing transmission of cattle nematodes if the two species are grazed together or alternately. 相似文献
6.
In an experiment it was shown that eggs of Ascaris suum, salmonella and fecal coliform bacteria mixed with sewage sludge and added to soil, will survive the first growing season. Most eggs of Ascaris suum in soil embryonated within a period of 7--15 weeks. In soil without a protective vegetation the concentration of eggs in the top soil layer 0--3 cm decreased faster than in soil with a protective vegetation. At the same time there seemed to be a corresponding increase in the concentration of eggs in the deeper layers of the soil. In the top layer, especially in the top soil without a protective vegetation, there was towards the end of the first growing season a higher per cent of dead eggs than in the deeper layers. The concentration of fecal coliform bacteria and salmonella was in the course of the first growing season reduced to 1/1000 and 1/10000, respectively, of the initial concentration. Infective Ascaris suum eggs and salmonella were found in washing water from vegetables grown in the first season. Infective Ascaris suum eggs were also present in soil in the second and third growing season. 相似文献
7.
High hydrostatic pressure processing (HPP) has been shown to be an effective non-thermal means of inactivating microorganisms from various food products. Little information is available regarding the effects of HPP on metazoan parasites. Outbreaks of food-borne disease have been associated with importation of food contaminated with fecal material. Ascaris suum is used as a surrogate model metazoan parasite for the human roundworm, Ascaris lumbricoides, to study the effects of treatments on the inactivation of eggs in sludge. The present study was conducted to determine the effects of HPP on A. suum eggs. Unembryonated A. suum eggs were subjected to 138-552 megapascals (MPa) for 10-60s in a commercial HPP unit. Embryonation was induced after HPP treatments by incubating eggs in 0.01N sulfuric acid at room temperature. After 21 days, 100 eggs were examined per treatment using a light microscope and the percent of embryonated eggs was determined. Embryonation was induced in 38-76% eggs that were subjected to 138 and 270MPa. No embryonation was observed in eggs exposed to pressures of 241MPa or more for 60s or in eggs exposed to 276MPa for 10-30s. These results indicate that HPP treatment could be used to protect contaminated food items by inactivating A. suum eggs and may also have potential in reducing food-borne illness resulting from fecal contamination. 相似文献
8.
Responses of swine to oral inoculation with embryonated eggs of Ascaris suum were monitored, using lymphocyte blastogenesis assays, indirect radioimmunoassays, and peripheral eosinophil counts (EC). Transient cell-mediated immune responses of peripheral lymphocytes were detected by lymphocyte blastogenesis assay as early as postinoculation day (PID) 2, but were rarely positive for consecutive samples taken at 2-day intervals. Humoral antibodies were first detected at PID 6 to 17 by indirect radioimmunoassays in the various experiments. Positive cutaneous delayed hypersensitivity reactions were observed when pigs were tested at 6 to 7 weeks after inoculation. Histopathologic examination verified infiltration of lymphocytes into the lesions. The EC increased as early as PID 4 to 7 and showed a secondary increase after the 2nd oral inoculation of eggs to as high as 11,400/mm3 (44% of the total WBC). Subsequently, EC decreased rapidly 14 days after the last inoculation of eggs. 相似文献
9.
In order to determine possible mediators for development of anorexia in pigs infected with Ascaris suum, serum levels of gastrin, insulin and glucagon were measured. After a single high oral dose of 100,000-200,000 embryonated eggs the serum levels of gastrin and insulin in the infected pigs did not significantly differ from those in controls. Serum glucagon levels in the infected groups, however, were lower than those in controls and the difference was more evident 24 days postinoculation and later. 相似文献
10.
This study was conducted on a stud farm in Sweden to investigate the species composition of cyathostomins expelled in the faeces of horses after deworming using three different anthelmintic preparations. Twenty-seven horses excreting > or = 200 strongyle eggs per gram faeces (EPG) were divided into three comparable groups and dewormed on day 0 with either of following compounds: 0.2 mg ivermectin per kg body weight (bw), 19 mg pyrantel pamoate per kg bw or 7.5 mg fenbendazole per kg bw. For each of the 3 days following anthelmintic treatment faeces was collected from individual horses and subsamples were fixed in formalin. Four days after the anthelmintic treatment all horses were re-treated with ivermectin and faeces was collected on day 5. Individual subsamples from each of the four sampling occasions were examined for cyathostomin nematodes. Sixty-three to 270 worms per horse were identified to the species level. The majority of the worms recovered were expelled during the first day from horses treated with ivermectin or pyrantel pamoate, and during the second day from horses treated with fenbendazole. Fifteen cyathostomin species were identified and the six most prevalent were Cylicocyclus nassatus, Cyathostomum catinatum, Cylicostephanus longibursatus, Cylicocyclus leptostomus, Cylicostephanus minutus and Cylicostephanus calicatus. These species composed 91% of the total burden of cyathostomins. The number of species found per horse ranged from 6 to 13, with an average of 9. No significant differences in species composition or distribution were found between the treatment groups. On day 5, i.e. 1 day after the last ivermectin treatment, 93% of the adult worms were recovered from horses in the fenbendazole group.This study showed that it was possible to identify cyathostomins expelled in faeces of dewormed horses, and that the most prevalent species corresponded to those found in autopsy surveys performed in other countries. 相似文献
11.
Four- to 8-week-old SPF pigs were immunized, using antigens of Ascaris suum incorporated into liposomes, via intestinal cannula or orally. Avridine was also incorporated in the liposomes in one experiment and interleukin-2 (IL-2) injected into pigs in another experiment. A priming dose of embryonate eggs (80-470 eggs/pig) were given in four of six experiments. Compared to control animals, the greatest protection of pigs to migrating ascarid larvae from a challenge dose of 10,000 embryonated eggs occurred where pigs received (1) a priming dose of eggs plus second-stage ascarid larval wall incorporated into liposomes, with or without avridine or IL-2, or (2) a priming dose of eggs plus ascarid intestinal aminopeptidase incorporated into liposomes with IL-2. The degree of protection was not statistically significant due, in part, to the variability in the responses of animals in the same treatment groups and the small number of animals per group. In general, only low titers of specific serum antibodies were detected and specific antibodies were not detected in the intestinal washing. 相似文献
12.
Pigs of 10 days-1 month old were orally infected with eggs of Ascaris suum at different rates and inoculation schedules. Histological sections from various parts of the small intestines were prepared to observe the production and localization of immunoglobulin-bearing cells. Fluorescent antibody and immunoperoxidase staining methods were used to determine the number of IgM-, IgA- and IgG-producing plasma cells in the intestinal lamina propria. Significant increases in immunoglobulin-bearing cells were observed in those pigs which received single inoculations of A. suum eggs. Pigs infected every 2,4,8 and 10 days with 10,000-20,000 embryonated eggs showed numerical increases in IgM-bearing cells. Increases in IgA-bearing cells were noted in pigs which received the higher number of eggs every 8-10 days. Higher concentrations of IgA- and IgM-bearing cells were observed in the jejunal mucosa of infected pigs as compared to those in the duodenum and ileum. 相似文献
13.
R.J. Jørgensen P. Nansen K. Nielsen L. Eriksen S. Andersen 《Veterinary parasitology》1975,1(2):151-157
Groups of piglets 20 to 28 days of age were dosed with 50 or 10 000 Ascaris suum eggs. The pigs were sacrificed from day 16 post infection onwards and worms present in the intestine were counted. Large numbers of immature parasites were recovered initially following the 10 000 egg dose, but the numbers decreased rapidly with the and worms were not found in pigs examined in the late prepatent phase. All pigletts infected with 50 eggs were found to harbour worms and the infection reached patency. The high level infections resulted in an eosinophil response which reached maximum values during the second week after infection. The low level infections which resulted in patency were not followed by any significant eosinophil response. 相似文献
14.
We here describe the transmission of the pig roundworm, Ascaris suum to chimpanzees maintained in the Copenhagen Zoo, Denmark. Using a technique for whole genome fingerprinting, amplified fragment length polymorphism (AFLP) and the technique PCR restricted fragment length polymorphism (PCR-RFLP) of the internal transcribed spacer region (ITS) of the nuclear ribosomal DNA, the worms from the chimpanzees were compared with Ascaris spp obtained from humans and pigs in order to identify the source of the infection. By the use of different distance and clustering based methods on the AFLP data set the worms from the chimpanzees were assigned to the same cluster as that of the worms from pigs. The PCR-RFLP analysis supported the AFLP results. Therefore, the zoo chimpanzees have required Ascaris infections by cross-infection from pigs. Pigs as a potential source of Ascaris infections for both captive and wild chimpanzees and other animals, therefore needs to be considered and appropriate steps taken to prevent such infection. 相似文献
15.
Rolf Jess Jrgensen 《Acta veterinaria Scandinavica》1978,19(1):147
Eggs from the pig roundworm Ascaris suum are easily obtainable in large numbers from uterus of adult worms. It is therefore natural that eggs isolated from that organ have been used almost exclusively in experimental ascariasis, both in the natural host (Kelley & Nayak 1965, Gaafar & Keittevuti 1972, Andersen et al. 1973, Jørgensen et al. 1975 and others) and in small laboratory animals (Jeska et al. 1969, Berger 1971 and others). In some cases no details are given on the origin and preparation of the infective eggs or the eggs may originate both from uteri of adult worms and from pig faeces (Kelley et al. 1957). 相似文献
16.
Nsoso SJ Mosala KP Ndebele RT Ramabu SS 《The Onderstepoort journal of veterinary research》2000,67(3):217-220
Botswana imports most pig-based products from neighbouring countries. Pig farming is limited by, among other things, the negative effect of parasites and diseases on production. The object of this study was to determine the prevalence of ecto- and endoparasites in pigs of different ages and sexes in the Southeast District of Botswana. Thirty-nine pigs were sampled for endoparasites and 19 for ectoparasites during a period of 2 1/2 months. Of all the pigs sampled, 54,55% were infected with Ascaris suum, 20,45% with Trichostrongylus spp. and 6,82% with Trichuris suis. Ascaris suum was found to be the most common endoparasite infesting both mature, i.e. 12 months and older, and young, i.e. less than 12 months old, pigs. Although not significantly different (P > 0,05), the prevalence of this parasite species was slightly higher (68,42% with an average of 1,023 +/- 545 eggs per gram (EPG) of faeces per pig) in mature than in young pigs (55% with an of average 1,500 +/- 846 EPG of faeces per pig). The prevalence of Trichostrongylus spp. was lower in mature (5,26% with 20 +/- 14 EPG of faeces per pig) than in young pigs (25% with 22 +/- 9 EPG of faeces per pig). The prevalence of T. suis was also lower in mature (0% infection) than in young pigs (15% with 9 +/- 4 EPG of faeces per pig). The prevalence of the three endoparasite species was not significantly different between the sexes A. suum (1,020 +/- 883 v. 1,503 +/- 522 EPG of faeces per pig), Trichostrongylus spp. (24 +/- 14 v. 18 +/- 8 EPG of faeces per pig) and T. suis (11 +/- 6 v. 2 +/- 4 EPG of faeces per pig) for male and female pigs respectively. Sarcoptes scabiei was the only ectoparasite identified on the pigs sampled for external parasites. It infested 40% of all pigs but the infestation on young pigs (70%) was higher than on the mature ones (33,33%). Since the infection of internal and external parasites was similar in young and old pigs of both sexes, controlling parasites is of great importance since these generally lead to reduced production and are also of public health concern. It is recommended that a further study be carried out to investigate the effect of internal and external parasites on productivity. 相似文献
17.
M Luzón-Pe?a F A Rojo-Vázquez M Gómez-Bautista 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1992,39(5):369-375
In this experimental work, conducted over two consecutive years (1988 and 1989), we have analyzed the overwintering possibilities of Fasciola hepatica eggs deposited in winter in a semi-arid and temperate Mediterranean area (Madrid, Spain). Eggs did not survive for more than a week in faeces at environmental moisture conditions. In contrast, over a 75% of the eggs maintained in permanently wet faeces survived winter temperatures, showing no high mortality until important thermic increment from June. The success of overwintering was higher in eggs arrested in wet faeces than included in water (55% "versus" 20% of hatching in spring), and it was unrelated to the deposition time (excretion in early or late winter). The hatching period of overwintered eggs started in May, at the same time as those excreted in early spring. Therefore, overwintering of eggs will have an effect on the level but not on the start of the spring contamination with miracidia. The dry winters of this semi-arid area greatly restrict the overwintering eggs contamination to soils next to streams, ponds or irrigation channels. 相似文献
18.
In two small farms in Sweden young calves were found to be naturally infected with Ascaris suum. One of the calves expelled mature worms with the faeces, one had a great number of worms in the ductus choledochus and two others had worms in the intestine. Most of the worms were mature and at the egg-producing stage. The morphology of the eggs and the adult worms indicated that these parasites were A. suum and that Toxocara (syn. Neoascaris) vitulorum could be excluded. 相似文献
19.
Perienteric fluid (Pf) of adult Ascaris suum was fractionated by ammonium sulfate precipitation, gel filtration or DEAE-cellulose chromatography, and sucrose density gradient centrifugation. Anti-sera (anti-EE) from pigs which were inoculated orally with fully embryonated eggs (EE) of A. suum were used in an indirect radioimmunoassay (IRIA) to determine which fractions of Pf reacted positively in the analyses at the lowest protein concentration. These fractions were considered to contain more potent antigens. Comparative IRIA were performed employing antisera (anti-Pf) produced by injecting Pf into pigs. Six out of 35 fractions reacted positively at ? 0.2 μg protein when anti-EE was used in the IRIA. Twenty-two out of 35 fractions reacted positively at ? 0.2 μg protein when anti-Pf was used. Five of the 6 fractions reacting positively with anti-EE also reacted with anti-Pf. A 76 000 dalton component appears to be one of the major proteins in the 6 fractions which react positively with anti-EE while components from 10 000–138 000 daltons were present in the various fractions reacting positively with anti-Pf at ? 0.2 μg protein. 相似文献
20.
The aim of this study was to examine interactions between Ascaris suum and Oesophagostomum dentatum infections in pigs with regard to population dynamics of the worms such as recovery, location and length; and host reactions such as weight gain, pathological changes in the liver and immune response. Seventy-two helminth-na?ve pigs were allocated into four groups. Group A was inoculated twice weekly with 10000 O. dentatum larvae for 8 weeks and subsequently challenge-infected with 1000 A. suum eggs, while Group B was infected with only 1000 A. suum eggs; Group C was inoculated twice weekly with 500 A. suum eggs for 8 weeks and subsequently challenge-infected with 5000 O. dentatum larvae, whereas Group D was given only 5000 O. dentatum larvae. All trickle infections continued until slaughter. Twelve pigs from Group A and B were slaughtered 10 days post challenge infection (p.c.i.) and the remaining 12 pigs from the each of the four groups were slaughtered 28 days p.c.i.. No clinical signs of parasitism were observed. The total worm burdens and the distributions of the challenge infection species were not influenced by previous primary trickle-infections with the heterologous species. Until day 10 p.c.i. the ELISA response between A. suum antigen and sera from the O. dentatum trickle infected pigs (Group A) pigs were significantly higher compared to the uninfected Group B. This was correlated with a significantly higher number of white spots on the liver surface both on Day 10 and 28 p.c.i. in Group A compared to Group B. The mean length of the adult O. dentatum worms was significantly reduced in the A. suum trickle infected group compared to the control group. These results indicate low level of interaction between the two parasite species investigated. 相似文献