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1.
猪食道口线虫ITS-1和lTS-2 rDNA的PCR-SSCP分析 总被引：1，自引：0，他引：1
以采自我国不同地区猪体的食道口线虫虫株为研究对象,PCR扩增出ITS-1和ITS-2序列片段,然后采用单链构象多态性(SSCP)方法分析PCR产物,对不同地区食道口线虫进行分子鉴定。所有样品经SSCP分析显示两种带型,第一种为有齿食道口线虫带型,另一种为未定种食道口线虫带型。代表性样品的测序结果表明,未定种食道口线虫带型的样品为四棘食道口线虫。本研究在国际上首次报道了中国猪四棘食道口线虫的ITS序列,并建立了区分有齿食道口线虫和四棘食道口线虫的PCR-SSCP方法,从而为食道口线虫的分子生物学的进一步研究奠定了基础。 相似文献
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3.
Forty pigs with induced infections of Ascaris suum, Trichuris suis, Metastrongylus spp., Oesophagostomum dentatum and O. quadrispinulatum were assigned to five-dose groups of moxidectin 0.5% pour-on with eight pigs per dose group. The doses were: moxidectin, 0 (vehicle control), 0.75, 1.00, 1.25, and 1.50 mg/kg(-1) body weight. Worm egg counts (EPG) were made from fecal samples collected on Day 2 pretreatment and on Day 14 or 15 post-treatment. Animals were ranked according to the descending order of A. suum egg counts made on Day 2 and blocked in groups of five. Pigs in blocked groups were assigned randomly to each of the five dose groups. Treatment doses were calculated on the basis of weights taken on Day 1 and were administered topically from the neck to the base of the tail. Pigs were housed by pairs in individual pens provided with self-feeders and automatic waterers. Necropsies were performed on equal numbers of pigs from each treatment group on days 14 and 15 post-treatment. Adult and larval worms were collected, identified and counted by standard parasitological techniques. All counts were transformed by Y=log10 (count+1) transformation prior to analysis. A two-way analysis of variance was conducted and treatment effect was tested for significance at the 5% level. Efficacies based on geometric means and optimal doses were as follows: Ascaris suum, 98.3% at 1.25; Metastrongylus spp., 100% at 0.75; Oesophagostomum quadrispinulatum, 100% at 1.50; and Trichuris suis, 93.5% at 0.75. Efficacy for O. dentatum was from 81.3% to 100%; however, the average number of O. dentatum (30) was too small for significance. Two species of lungworms were present, Metastrongylus apri and M. pudendotectus but they were not speciated at necropsy. As reported for several anthelmintics, the efficacy of moxidectin was variable for Trichuris. The highest efficacy was in the 0.75 dose group with six pigs harboring a few or no worms. The lowest efficacy was in the 1.25 group with only two pigs harboring a few or no worms. 相似文献
4.
Steenhard NR Roepstorff A Baggesen DL Boes J Jensen TK Aasted B Ørnbjerg N 《Veterinary parasitology》2006,139(1-3):158-167
Concomitant infections with helminths and bacteria may affect the course and the resulting disease outcome of the individual infections. Salmonella, Oesophagostomum, Trichuris and Ascaris coexist naturally in pig herds in Denmark, and possible interactions were studied. Pigs in one experiment were trickle infected with low or moderate dose levels of Oesophagostomum spp. and challenge infected with S. Typhimurium. In another experiment, pigs were inoculated with S. Typhimurium followed by a challenge exposure to either Oesophagostomum, Trichuris or Ascaris. Enhancement of the Salmonella infection was not demonstrated in either experiment. The helminth effect on the pigs was modest and may explain the lack of influence on the Salmonella infection. A previous experiment with a larger Oesophagostomum infection level resulted in enhancement of the S. Typhimurium infection. A dose dependency of the interaction is therefore suggested. However, the relatively high worm burdens in the present study suggest that infection with these common pig helminths does generally not influence the course of concurrent S. Typhimurium infections under natural conditions. 相似文献
5.
This study was undertaken to determine the level of resistance against pyrantel citrate in strains of Oesophagostomum quadrispinulatum and Oesophagostomum dentatum which have previously been found resistant to this anthelmintic. Groups of pigs were artificially infected with batches of infective larvae which were previously found either susceptible or resistant to pyrantel citrate. After treatment with 1, 2 and 4 times the recommended dose (14 mg kg-1) of pyrantel citrate, the resistant O. quadrispinulatum population was reduced by 51.0, 76.2 and 86.1%, and O. dentatum by 41.2, 47.9 and 78.5%. The results indicated that O. dentatum was slightly more resistant (P less than 0.05) than O. quadrispinulatum to pyrantel citrate. Treatment of the susceptible worms with 1 and 2 times the recommended dose caused a reduction in worm numbers by 61.0 and 99.4%, respectively. 相似文献
6.
Two strains of Oesophagostomum spp., consisting of both O. quadrispinulatum and O. dentatum, were subjected to a controlled in vivo assay for resistance to levamisole and pyrantel by comparison with susceptible isolates. One strain (LEM) was recently isolated from a commercial herd, where sows showed high numbers of strongyle eggs in faeces within 2 weeks of farrowing and following treatment with levamisole at the manufacturer's recommended dose rate 1 week before farrowing. Levamisole had been used as the sole anthelmintic for treatment for at least 7 years on this farm. Treatment with pyrantel in this herd also indicated cross-resistance to this drug. A mixed population of O. quadrispinulatum and O. dentatum of this strain was subjected to controlled in vivo assays. Faecal egg count reduction (FECR) was found to be -573.3% (P greater than 0.05) and worm count reductions (WCR) of O. quadrispinulatum and O. dentatum were estimated as 44.5% (P greater than 0.05) and 96.4% (P less than 0.001), respectively. Treatment with pyrantel showed that cross-resistance existed to this drug, with FECR of 10.4% (P greater than 0.05) and WCR of 64.5% (P greater than 0.05) and 90.7% (P less than 0.05) for O. quadrispinulatum and O. dentatum, respectively. Another strain (VJ) was isolated from another commercial pig herd, which was dosed with pyrantel citrate four times a year for at least 8 years. This strain showed resistance to pyrantel, with FECR of 43.8% (P greater than 0.05) and WCR of 65.9% (P greater than 0.05) and 49.4% (P greater than 0.05) for O. quadrispinulatum and O. dentatum, respectively. However, both species were susceptible to levamisole. Our results suggested that selection with levamisole gave rise to levamisole resistance and automatically conferred resistance to pyrantel, whereas selection with pyrantel only resulted in resistance to this drug alone. These findings are discussed in relation to the location of the two species of Oesophagostomum in the large intestine of pigs and the mode of action of this class of anthelmintics. 相似文献
7.
N D Primm W F Hall J A DiPietro D P Bane 《American journal of veterinary research》1992,53(4):508-512
In 2 trials, the efficacy of an in-feed preparation of ivermectin was evaluated in 40 pigs naturally infected with endoparasites and Sarcoptes scabiei var suis. Treated pigs (n = 10 in each trial) were fed a ration containing 2 ppm ivermectin for 7 days, followed by consumption of a nonmedicated ration for the remainder of the trial. Control pigs (n = 10 in each trial) were fed a complete, nonmedicated ration for the duration of the trial. Pigs in trial A were monitored for 14 days after treatment; those in trial B were monitored for 35 days after treatment. In trial A, treatment efficacy of ivermectin was 100% against Ascaris suum, Physocephalus sexalatus, Oesophagostomum dentatum, O brevicaudum, Metastrongylus spp; 99.8% against Ascarops strongylina; 90.9% against Trichuris suis; and 13.1% against Macracanthorhynchus hirudinaceus. At the terminus of the trial, statistically significant (P less than 0.05) differences were observed between numbers of treated and control pigs infected with A suum, Ascarops strongylina, and Oesophagostomum spp. On posttreatment day 14, S scabiei were not found in any scrapings taken from treated pigs, but were found in scrapings from 3 of 10 control pigs. The number of infested pigs in the treatment group was not statistically different from the number of infested pigs in the control group. In trial B, treatment efficacy was 100% for A suum and Metastrongylus spp; 96.9% for Ascarops strongylina; and 76.9% for M hirudinaceus. At the terminus of the trial, statistically significant (P less than 0.05) differences were evident between numbers of treated and control pigs infected with A suum, Ascarops strongylina, and Metastrongylus spp.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
8.
Borgsteede FH Gaasenbeek CP Nicoll S Domangue RJ Abbott EM 《Veterinary parasitology》2007,146(3-4):288-293
A study was conducted to evaluate and compare the efficacy of two injectable formulations of ivermectin (IVM-1 and IVM-2) at a dose rate of 0.3 mg/kg bodyweight versus placebo in the treatment and control of larval and adult stages of Ascaris suum and Oesophagostomum spp. in experimentally infected pigs. Seventy helminth free pigs were allocated on a liveweight basis to 7 groups each comprising 10 pigs (A-G). Group A served as an untreated control group. Groups B and C were used to investigate the efficacy of both formulations against adult stages of A. suum and Oesophagostomum spp., Groups D and E for efficacy against larval stages of A. suum and Groups F and G for efficacy against larval stages of Oesophagostomum spp. Pigs of groups A, B, C, D and E were infected on Day-0 with 1000 infective A. suum eggs each. Infective larvae of Oesophagostomum spp. (10,000/pig) were given on Day-0 to pigs of Groups F and G and on Day-21 to pigs of Groups A, B and C. Treatment was given to pigs of Group A (saline as placebo) on Day-7 and -28, IVM-1 to pigs of Group F on Day-7, pigs of Group D on Day-14 and pigs of Group B on Day-49. IVM-2 was given to pigs of Group G on Day-7, Group E on Day-28 and Group C on Day-49. Pigs of Groups F and G were sacrificed on Day-28, pigs of Groups A, D and E on Day-49 and pigs of Groups B and C on Day-56. Post mortem worm counts showed the following efficacies: (IVM-1) against larval A. suum 100%, against adult A. suum 94.4%, against larval Oesophagostomum spp. 52.0% and against adult Oesophagostomum spp. 83.0%. (IVM-2) against larval A. suum 100%, against adult A. suum 90.3%, against larval Oesophagostomum spp. 94.0% and against adult Oesophagostomum spp. 94.7%. 相似文献
9.
The in vitro activities of thiabendazole, levamisole, pyrantel, morantel and ivermectin against Oesophagostomum spp., the nodular worm of pigs, were determined and compared. The study was carried out using isolates of O. dentatum and O. quadrispinulatum, which had been defined in vivo. Infective larvae were exposed to the anthelmintics for 24 h and then placed in a micromotility meter. All the treatments significantly reduced the motility of the ensheathed L3 larvae, but the micromotility meter was not able to differentiate between anthelmintic resistant and anthelmintic susceptible isolates. 相似文献
10.
Field experiments carried out in the Maritime area of Canada failed to demonstrate overwinter survival of porcine nodular worms, Oesophagostomum quadrispinulatum and O. dentatum. Pastures were contaminated by carrier animals with subsequent transmission of infection to susceptible pigs. One approach to control of oesophagostomiasis in grazing swine is the treatment of all infected pigs prior to going on pasture. 相似文献
11.
This study was undertaken to determine whether anthelmintic-resistant Oesophagostomum spp. populations occur in Danish swine herds. A controlled field trial on selected sow herds suggested resistance to pyrantel citrate in a herd where faecal egg count depression in response to treatment was only 28.3%. This was confirmed by subsequent experimental infection of pigs where the suspected resistant Oesophagostomum isolate was compared with a susceptible worm isolate. After treatment with the recommended dose of the drug, worm burdens of the suspected isolate were only reduced by 42.6% (p greater than 0.05) in contrast to the susceptible isolate, which was reduced by 94.6% (p less than 0.01). Differential counts of the resistant isolate suggested that O. dentatum might be more resistant than O. quadrispinulatum. The resistant isolate originated from a herd, where the anthelmintic had been administered four times a year over a period of 7 years. The potential for development of anthelmintic resistance in Oesophagostomum spp. under management practices in our country is discussed in the light of the current views on predisposing factors. 相似文献
12.
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
13.
R Alva-Valdes D H Wallace J R Egerton G W Benz S J Gross J W Wooden V E Reuter 《American journal of veterinary research》1988,49(10):1726-1728
Twelve Holstein calves were used to determine the prophylactic efficacy of ivermectin against challenge exposure with gastrointestinal and pulmonary nematodes. Two groups of 6 calves (mean body weight, 205 kg) each were formed by restricted randomization according to body weight. Group-1 calves served as nonmedicated controls. Each calf of group 2 was orally given one prototype sustained-release bolus designed to deliver ivermectin at a continuous daily dose of 8 mg. Third-stage nematode infective larvae were given to the calves on posttreatment days 28 and 42. The calves were euthanatized 77 or 78 days after treatment. Ivermectin was 100% effective (P less than 0.05) in preventing the establishment of infection by Haemonchus placei, Ostertagia ostertagi, Cooperia spp (C punctata, C oncophora, C surnabada), Nematodirus helvetianus, Oesophagostomum radiatum, and Dictyocaulus viviparus and was greater than 99% effective against Trichostrongylus axei. Incidental infection by Trichuris spp was reduced by 94% (P = 0.08). 相似文献
14.
Interactions between the predacious fungus Arthrobotrys oligospora and third-stage larvae of a series of animal-parasitic nematodes 总被引：2，自引：0，他引：2
Interactions between the predacious hyphomycete Arthrobotrys oligospora and third-stage larvae of nine animal-parasitic nematodes were tested in vitro. The trap-inducing capabilities of the ruminant trichostrongylus Cooperia oncophora, C. curticei, Haemonchus contortus and Ostertagia ostertagi and of equine cyathostomes were almost comparable to those of free-living soil nematodes, and significantly higher than those of the porcine Oesophagostomum dentatum and Oe. quadrispinulatum and of the murine Nematospiroides dubius. The trap-forming potential of Dictyocaulus viviparus was poor. All animal-parasitic nematodes were rapidly captured when fungal traps had been pre-induced in high numbers. The possible influence of predacious fungi on animal-parasitic nematode populations under natural conditions in the field is discussed. 相似文献
15.
Frana TS Carlson SA Rauser DC Jones BD Fergen BJ Griffith RW 《American journal of veterinary research》2004,65(12):1616-1620
OBJECTIVE: To investigate the effect of an Escherichia that produced microcin 24 (Mcc24) on shedding of of Salmonella enterica serotypeTyphimurium in swine and evaluate evidence of in vivo activation of the Mcc24-mediated, multiple-antibiotic resistance (mar) operon. ANIMALS: 36 crossbred weaned pigs. PROCEDURE: 24 pigs were allocated to 2 groups (12 pigs/group). Pigs in 1 group received daily oral administration of an Mcc24-producing E coli, whereas the other group received a non-Mcc24-producing E coli. All pigs were challenge exposed with Salmonella Typhimurium chi4232. A third group of 6 pigs received Mcc24-producing E coli and was challenge exposed with an Mcc24-sensitive, marA-deleted strain of Salmonella Typhimurium 4232. After challenge exposure, fecal samples from all pigs were cultured to detect shedding of Salmonella Typhimurium and Salmonella Typhimurium isolates were screened for resistance to ciprofloxacin. Fecal samples were collected throughout the study, and tissue samples were collected during necropsy. RESULTS: Differences in shedding of Salmonella Typhimurium were not detected between groups receiving Mcc24-producing or non-Mcc24-producing E coli. No significant differences were found in quantitative analysis between groups receiving Mcc24-producing and non-Mcc24-producing E coli. Evidence of mar activation was not detected. CONCLUSIONS AND CLINICAL RELEVANCE: Microcin-producing E coli did not exert an effect on shedding of SalmonellaTyphimurium or mar activation in pigs. It may be difficult or impractical to create the conditions required for Mcc24 to be an effective part of a food safety intervention to reduce shedding of Salmonella Typhimurium. 相似文献
16.
Permin A Yelifari L Bloch P Steenhard N Hansen NP Nansen P 《Veterinary parasitology》1999,87(1):63-71
A cross-sectional study was carried out in the Upper East Region (UER) of Ghana in order to estimate the prevalence of parasitic infections in local cross-bred pigs. Out of 60 villages with a human population of 200-1000 inhabitants, 10 villages were randomly selected for the study. The number of pigs varied from 50 to 200 pigs per village. In total 259 faecal samples from growers were collected and examined. Ninety-one percent of the animals excreted parasite eggs. Among these the prevalence of Eimeria spp. was 77.2%, Isospora suis (27%) and Balantidium coli (19.3%).The following helminth eggs were identified: Metastrongylus salmi (19.3%); Physocephalus sexalatus (17.4%); Oesophagostomum spp./Hyostrongylus rubidus (60.6%); Trichuris suis (4.6%); Ascaris suum (12.7%); Ascarops strongylina (8.1%); Brachylaemus suis (1.9%); Paragonimus suis (0.8%); Globocephalus urosubulatus (2.7%); and Schistosoma suis (0.4%). Furthermore, six growers were selected from each village for clinical and postmortem examinations, i.e. 60 in total. The clinical examinations revealed ectoparasites on 98.3% of the animals. The ectoparasites were: Haematopinus suis (66.7%); Boophilus spp. (58.3%); Amblyomma spp (45.0%); Sarcoptes suis (38.3%); and Rhipicephalus spp. (8.3%). All pigs were examined for the presence of haemoparasites. It was found that 23.3% of the animals had haemoparasites. These were: Babesia perroncitoi (23.3%); Babesia trautmanni (13.3%); and Eperytrozoon suis (1.7%). Based on postmortem examinations the following adult worms were identified: Metastrongylus salmi (83.3%); Oesophagostomum dentatum (63.3%); Oesophagostomum quadrispinulatum (38.3%); Hyostrongylus rubidus (23.3%); Ascarops strongylina (76.7%); Globocephalus urosubulatus (20.0%); Strongyloides spp. (1.7%); and Physocephalus sexalatus (65.0%). Cysts of the human tapeworm Taenia solium, Cysticercus cellulosae, were present in 11.7% of the animals. Small pieces of the diaphragm were examined for the presence of Sarcocystis spp.. The prevalence was 28.3%, but no larvae of Trichinella spp. were found. Furthermore, four of the animals (6.7%) had Taenia hydatigena cysts. 相似文献
17.
Efficacy of tiamulin against experimentally induced Streptococcus suis type-2 infection in swine 总被引：2，自引：0，他引：2
M M Chengappa L W Pace J A Williams C H Herren S E Ascher 《Journal of the American Veterinary Medical Association》1990,197(11):1467-1470
Eighteen 4-week-old pigs were used in a study to evaluate tiamulin in drinking water for control of experimentally induced Streptococcus suis type-2 infection. Pigs in groups A and B (n = 6 pigs/group) were aerosolized with a logarithmic-growth phase culture of S suis type 2, whereas pigs in group C (n = 6 pigs) served as noninfected and nonmedicated controls. After exposure to S suis, pigs in group B were given 180 mg of tiamulin/L of drinking water for 5 days. Pigs in group B consumed more feed (P = 0.009) and gained body weight faster (P = 0.02) than did pigs in group A. Pigs in group A had higher rectal temperature (P = 0.05) for up to 7 days after S suis exposure, higher clinical sign scores (P = 0.008), higher serum cortisol concentration on days 7 and 14, higher gross lesion scores (P = 0.03), and higher microscopic lesion scores (P = 0.01) than did pigs in groups B and C. Gross and microscopic lesions in pigs of groups A and B included meningitis, pneumonia, pleuritis, pericarditis, peritonitis, and synovitis of variable severity. Streptococcus suis type 2 was recovered from tissue specimens of 2 group-A pigs and 1 group-B pig. Data indicated that tiamulin administered via drinking water significantly reduced the effects of S suis type-2 infection. 相似文献
18.
The effects of Oesophagostomum dentatum infection and dietary carbohydrates on the morphology and epithelial cell proliferation in the gastrointestinal tract of pigs were investigated experimentally. Thirty-two worm-free pigs (n=32) from a specific pathogen-free farm were randomly divided into four groups (A-D), of eight animals each. Pigs in groups A (control) and B (infected) were fed Diet 1, and pigs in groups C (control) and D (infected) were fed Diet 2. The two diets were formulated: Diet 1 (%) contained barley flour, oat husk meal plus soya bean meal (55:21:24) and Diet 2 (%) contained barley flour, inulin and sugar beet fibre (SBF) (80.1:7:12.9) plus soya bean meal (3:1) to contain carbohydrates from inulin and sugar beet fibre (SBF) that were readily fermentable in the large intestine. The two infected pig groups (16 pigs total) were inoculated with 6000 infective larvae of O. dentatum and all pigs, including the controls, were slaughtered 12 weeks p.i. The combination of O. dentatum infection and highly fermentable dietary carbohydrates affected the mucosal architecture, the epithelial cell proliferation and mucin secretion of the large intestine. Infection had a significant influence on the crypt volume, height and density, and on muscularis externa at the proximal and middle colon. The changes in the affected gut sections were proportional to the number of worms present. However, these parameters appeared unaffected by those diets alone. In pigs without infection non-digestible dietary carbohydrates significantly influenced the tissue weight of colon. 相似文献
19.
The RH strain of Toxoplasma gondii is highly virulent; 1 infective organism is uniformly lethal for mice. Three pigs inoculated SC with 10(3) tachyzoites of the RH strain developed fever, but otherwise remained normal, and T gondii was not demonstrated in their tissues by bioassay into mice. To determine whether vaccination with the RH strain could induce protective immunity to oral challenge with T gondii oocysts, 12 pigs were divided into 3 groups (A, B, C) of 4 pigs each. Pigs in groups A and B were inoculated IM with 10(6) tachyzoites of the RH strain and 4 pigs in group C served as uninoculated controls. Except for fever, the pigs remained clinically normal after inoculation with the RH strain and T gondii was not found by bioassay in mice of tissues from 4 pigs euthanatized 64 days after inoculation. Pigs in groups B and C were challenge-inoculated orally with 10(4) (4 pigs) or 10(5) (4 pigs) T gondii oocysts 72 days after vaccination with the RH strain. The previously uninoculated pigs developed fever, anorexia, and diarrhea from 3 to 8 days after the oocyst challenge. One of the 2 pigs given 10(5) oocysts became moribund because of toxoplasmosis and was euthanatized 9 days after inoculation. Pigs vaccinated with the RH strain remained free of clinical signs after challenge with oocysts. Results of the bioassays indicated that fewer tissue cysts developed in the RH strain-vaccinated pigs than in the previously uninoculated control pigs. 相似文献
20.
A controlled trial was performed to evaluate the efficacy of piperazine dihydrochloride in a new granular formulation (Ascarex D) against naturally occurring infections with Ascaris suum, Oesophagostomum dentatum and O quadrispinulatum. Treatment effects were estimated on the basis of parasites recoverable from the intestinal contents. Given orally at 200 mg per kg body weight the compound showed an efficacy of 99 to 100 per cent against A suum and the nodular worms. Egg excretion of the respective species was reduced by 98 per cent and 100 per cent six days after treatment. No adverse reactions were observed after the treatment. 相似文献