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1.
Enzyme immunoassays using the triple antibody enzyme linked immunosorbent assay (ELISA) with both Trichinella spiralis spiralis and T. spiralis nativa excretory-secretory (ES) antigens and a commercial Trichinella spiralis enzyme immunoassay test kit were carried out on sera from pigs that were infected with light, moderate and high doses of infective T. spiralis spiralis and T. spiralis nativa respectively. Seroconversion occurred in all pigs given infective Trichinella larvae although no trichinae were recovered from pigs given T. spiralis nativa larvae and examined between days 92 and 99 postinfection by pepsin digestion. Anti-Trichinella antibodies were detected in pigs infected with T. spiralis spiralis and T. spiralis nativa by ELISA using either the homologous or heterologous ES antigen. The commercial Trichinella spiralis enzyme immunoassay test kit also detected anti-Trichinella antibodies in both the T. spiralis spiralis and T. spiralis nativa infected pigs. The commercial test kit did not appear to be as sensitive as the triple antibody ELISA since it usually took two to three days longer for seroconversion to be detected by the former procedure. Finally seroconversion occurred more rapidly in swine infected with T. spiralis spiralis than with pigs receiving comparable doses of T. spiralis nativa.  相似文献   

2.
The infectivity of Trichinella spiralis nativa isolates from widely separated geographic areas of Canada was determined by feeding infected musculature to swine, laboratory rats and carnivores (cats, foxes, ferrets). Low infectivity for swine and rats and high infectivity for carnivores were observed. Light infections were established in four of 16 swine examined between 25 and 53 days postinfection. Feeding of infected porcine musculature to ferrets demonstrated that Trichinella spiralis nativa can be passaged through swine even though the infectivity rate is low.  相似文献   

3.
An enzyme-linked immunosorbent assay (ELISA) using excretory-secretory antigens was developed to study the dynamics of the IgG antibody response to varying levels of Trichinella spiralis infection in the guinea pig. Four groups of four Hartley guinea pigs each were infected with 1250, 250, 50 or 10 T. spiralis infective muscle larvae. They were bled every 15 days for 6 months and the IgG antibody response determined by ELISA. The time of seroconversion was dose dependent as the larger the dose, the earlier the response occurred. Significant differences in antibody response between the dose groups were evident at 30 days post-infection (P less than 0.05). Beyond 60 days post-infection, the response was similar in the four groups. The antibody response in the groups infected with 250 and 50 infective larvae was similar, but was significantly different from that of the high (1250) and low (10) dose groups from 30 days post-infection (P less than 0.01). Once seroconversion occurred, the antibody titer rose to the same level, irrespective of the initial dose. To compare the antibody response according to muscle larvae recovered, the guinea pigs were grouped into four categories: less than 10 larvae; 10-25 larvae, 50-80 larvae, greater than 100 larvae. A significant positive correlation (P less than 0.05) was observed at 60 days post-infection when these groups were compared.  相似文献   

4.
A refrigeration technique to differentiate the subspecies, Trichinella spiralis spiralis and T. spiralis nativa is described. Trichinella spiralis spiralis trichinae in musculature do not survive 48 hours post-refrigeration at -32 degrees C while T. spiralis nativa will survive 72 hours and longer at the same temperature.  相似文献   

5.
The influence of preconditioning temperature, length of the preconditioning period, host and age of the infection on the survival of Trichinella spiralis nativa larvae in musculature to low temperature refrigeration was investigated. Dogs, foxes, ferrets, mink and guinea pigs were infected with a T. spiralis nativa isolate, killed at various times postinfection, preconditioned at temperature of -10 degrees C, -15 degrees C or -20 degrees C for varying periods of time prior to low temperature refrigeration and subsequent pepsin digestion to determine survival of larvae. The preconditioning temperature played an important role in the subsequent survival of larvae in musculature at low refrigeration temperatures. Under the conditions of this study, survival of larvae was greater as the preconditioning temperature became lower. The minimum period of preconditioning required had an inverse relationship with the refrigeration temperature. Preconditioning of the T. spiralis nativa isolate used occurred in the musculature of guinea pigs, foxes, ferrets, mink and dogs with larvae surviving longer in vulpine and canine musculature than in the other hosts studied. Age of the infection was not a major factor in the survival of preconditioned larvae in musculature at low refrigeration temperatures although survival was slightly longer in older infections.  相似文献   

6.
Rats and pigs were vaccinated against Trichinella spiralis spiralis either by feeding infective larvae of the subspecies, Trichinella spiralis nativa in musculature or by gavage. The number of larvae established in the musculature of vaccinated nonchallenged and vaccinated challenged rats and pigs were negligible and statistically comparable, while highly significant infections were established in the nonvaccinated challenged rats and pigs. High vaccination doses of T. spiralis nativa gave virtually complete protection to challenge with T. spiralis spiralis in pigs. The results of one trial in rats with a lower vaccination dose of larvae suggest that there is a minimal vaccination dose of larvae required to elicit marked resistance to challenge. The low numbers of muscle larvae established due to the high vaccination doses of larvae confirm the low infectivity of the subspecies, T. spiralis nativa in rats and pigs.  相似文献   

7.
Enzyme-linked immunosorbent assay examination of sera from pigs vaccinated with T. spiralis nativa infective larvae and/or challenged with T. spiralis spiralis larvae using a T. spiralis spiralis excretory-secretory antigen showed a significant cross-reaction between the two species of Trichinella. Eight of 12 pigs vaccinated with a high dose of T. spiralis nativa reacted positively 28 days postvaccination while the remaining four pigs had high but negative ELISA optical density readings. Five of six pigs challenged with the homologous species reacted positively 28 days postchallenge but the sixth pig remained negative despite having a muscle infection of 5.6 larvae/g of musculature.  相似文献   

8.
本试验通过差速超速离心法获得旋毛虫肌幼虫期胞外囊泡(Trichinella spiralis muscle larvae extracellular vesicles,Ts-ML-EVs),经透射电镜观察、纳米颗粒追踪分析、流式细胞术和Western blot鉴定。选择6～8周龄的健康雌性BALB/c小鼠,随机分为4组,每组8只。试验设计为PBS对照组(PBS组)、佐剂对照组(PBS+佐剂组)、旋毛虫肌幼虫期排泄分泌产物免疫组(Ts-ML-ES+佐剂组)以及旋毛虫肌幼虫期胞外囊泡免疫组(Ts-ML-EVs+佐剂组),分别取相应抗原与佐剂等体积混合采用多点皮下注射方式免疫小鼠。首免后第2,4周各加强免疫1次,剂量不变。三免后2周,每只小鼠灌胃300条旋毛虫肌幼虫,灌胃后6 d每组取2只剖杀,统计旋毛虫成虫减虫结果;攻虫35 d后所有小鼠全部处死,计算肌幼虫减虫率。每次免疫前、攻虫前以及处死前眼眶采血收集血清并保存,统一进行ELISA分析。结果显示：成功获得Ts-ML-EVs,随着免疫次数增加,小鼠血清中特异性IgG、IgG1、IgG2a、IgA和IgE抗体水平均显著上升,在三免后2周达到...  相似文献   

9.
The horse is considered an aberrant host for the nematode parasite Trichinella spiralis, and many aspects of the biology and epidemiology of Trichinella infection in the horse are poorly understood. It has been reported that experimentally-infected horses produce a transient serological response to infection and that muscle larvae are cleared more rapidly than in parasite-adapted hosts such as the pig and humans. However, limited numbers of animals have been studied, and both the longevity of larvae in horse musculature and the immune response to Trichinella larvae remain unclear. In this study, we infected 35 horses with 1000, 5000, or 10,000 T. spiralis muscle larvae and followed the course of infection for 1 year, assessing larval burdens in selected muscles, the condition and infectivity of recovered larvae, and the serological response of infected horses. The results demonstrated that T. spiralis establishes infection in horses in a dose dependent manner. Anti-Trichinella IgG antibodies peaked between weeks 6-10 post-inoculation. Viable, infective larvae persisted in horse musculature for the duration of the study (12 months), and exhibited no apparent reduction in muscle burdens over this period. Encapsulated larvae showed no obvious signs of degeneration in histological sections. Larval capsules were surrounded by infiltrates consisting of mature plasma cells and eosinophils. Macrophages were notably absent. Given the lack of a detectable serological response by 26 weeks p.i. and the persistence of infective muscle larvae for at least 1 year, parasite recovery methods are currently the only suitable detection assays for both meat inspection and epidemiological studies of Trichinella infection in the horse.  相似文献   

10.
The aim of this study was to investigate possible influence of different helmintosis in the development of Trichinella spiralis in experimental infected pigs. Forty-two Iberian pigs were allocated to six groups. Three groups were single inoculated with Ascaris suum, Metastrongylus apri or T. spiralis, respectively. Two groups were co-infected with T. spiralis and A. suum or T. spiralis and M. apri, respectively, while the last group included uninfected control pigs. Clinical signs were only observed in pigs with single or concurrent M. apri infections, with more severe respiratory symptoms in pigs with mixed M. apri infection. The number of A. suum and M. apri lung larvae, intestinal larvae of A. suum and adult M. apri were reduced in pigs with mixed Trichinella infections compared to pigs with single infections. In contrast, the number of liver white spots was higher in pigs with mixed infections. While T. spiralis muscular larval burdens were increased in pigs concomitantly infected with M. apri, they were reduced in pigs concomitantly infected with A. suum, compared to pigs receiving single infections with either of these helminths. Pigs with single or mixed A. suum infections showed higher eosinophil levels compared to the remaining groups. IgGt, IgG1, IgG2 and IgM against T. spiralis antigen could not be detected in pigs with single Ascaris or Metastrongylus infections, indicating that no cross-antibodies were produced. IgGt, IgG1 and IgM antibodies were detected earlier and generally at higher levels in mixed T. spiralis infections compared to single T. spiralis infections. The results suggest that T. spiralis had a low synergistic interaction with M. apri in concomitantly infected pigs, and an antagonistic interaction in concurrent infection with A. suum.  相似文献   

11.
Preconditioning of a Trichinella spiralis nativa isolate in ferret and fox musculature was carried out by freezing at -15 degrees C from 0 to 322 days prior to low temperature refrigeration at -32 degrees C. A limited number of preconditioned samples of infected fox musculature was also refrigerated at -45 degrees C. Preconditioned larvae were appreciably more resistant than those subjected to the low temperatures directly. Under the conditions of this investigation, the longer the period of preconditioning, the greater the resistance, (i.e., survival of larvae) observed. The larvae in fox musculature were slightly more resistant than those in ferret musculature. Limited infectivity trials indicated that pre-conditioned larvae surviving low temperature refrigeration of -32 degrees C -45 degrees C retained their infectivity for at least 44 and 37 days, respectively.  相似文献   

12.
Experimental trichinosis in sheep.   总被引：1，自引：1，他引：0       下载免费PDF全文
Trichinella spiralis spiralis infections were established in sheep by administering infective larvae via gavage or feeding infected musculature. Trichinella spiralis nativa infective larvae had a low infectivity for sheep although light infections may be established in some animals with large infective doses. For the most part, sheep were averse to ingesting musculature mixed in a grain ration unless it was camouflaged with molasses. The heaviest infections usually occurred in the masseter muscle. The fact that sheep are averse to ingesting muscle tissue may reduce the likelihood of trichinosis. Anti-Trichinella antibodies to both T: spiralis spiralis and T. spiralis nativa were produced as demonstrated by the enzyme-linked immunosorbent assay. Seroconversion occurred in several sheep challenged with T. spiralis nativa even though larvae were not recovered from the musculature by pepsin-digestion.  相似文献   

13.
The aim of this study was to examine the dynamics of parasite specific antibody development in Trichinella spiralis and Toxoplasma gondii co-infections in pigs and to compare these with antibody dynamics in T. spiralis and T. gondii single infections. In this experiment, fifty-four pigs were divided into five inoculated groups of ten animals, and one control group of four animals. Two groups were inoculated with a single dose of either T. gondii tissue cysts or T. spiralis muscle larvae, one group was inoculated simultaneously with both parasites and two groups were successively inoculated at an interval of four weeks. Specific IgG responses to the parasites were measured by ELISA. T. gondii burden was determined by MC-PCR carried out on heart muscle and T. spiralis burden by artificial digestion of diaphragm samples. Specific IgG responses to T. gondii and T. spiralis in single and simultaneously inoculated animals showed a respective T. gondii and T. spiralis inoculation effect but no significant interaction of these parasites to the development of specific antibodies with the serum dilutions used. Moreover, our data showed that the specific IgG response levels in groups of animals successively or simultaneously co-infected were independent of a respective previous or simultaneous infection with the other parasite. Additionally, no differences in parasite burden were found within groups inoculated with T. gondii and within groups inoculated with T. spiralis. Conclusively, for the infection doses tested in this experiment, the dynamics of specific antibody development does not differ between single and simultaneous or successive infection with T. gondii and T. spiralis. However, lower parasitic doses and other ratios of doses, like low-low, low-high and high-low of T. gondii and T. spiralis in co-infection, in combination with other time intervals between successive infections may have different outcomes and should therefore be studied in further detail.  相似文献   

14.
Vaccination of pigs against the helminth nematode Trichinella could be a good alternative to prevent the risk of human infection. In order to develop an efficient and safe vaccine, the choice of the adjuvant is an important issue. In this study, two adjuvants were selected to prepare vaccines based on total soluble Trichinella spiralis muscle larvae (ML) antigen: Montanide ISA 70 water in oil emulsion and Montanide IMS nanoparticles. Aluminium hydroxide was used as a reference adjuvant. The immune response was checked by ELISA of parasite antigen specific IgG1 and IgE. Finally, protection induced in vaccinated mice was measured after a T. spiralis challenge by counting ML burdens. The results clearly showed an impact of adjuvants on the specific IgG1 and IgE antibody responses against T. spiralis. Differences were observed between the rates of protection induced according to the type of formulation, although the three adjuvants tested were able to enhance the humoral immune response. This work demonstrated the need to use an adjuvant to obtain a specific IgG1 and IgE responses directed against the total soluble extract of T. spiralis.  相似文献   

15.
本研究旨在对重度感染旋毛虫后小鼠心肌损伤的研究。通过对小鼠接种旋毛虫,1 000条/只,分别于不同时间对血清中心肌损伤标志物H-FABP、CK-MB和cTnT进行动态检测,以及心肌组织病理形态学变化进行观察。结果显示,H-FABP比CK-MB、cTnT敏感性高(P<0.05),出现及达到高峰的时间最早;感染旋毛虫后19d～24d,心肌组织损伤最为严重。H-FABP可用于早期旋毛虫病患者心肌损伤的诊断,具有较高的敏感性和特异性。  相似文献   

16.
Experimental Trichinella infections in ponies.   总被引：2，自引：2，他引：0       下载免费PDF全文
Light Trichinella infections were established in three ponies given 1000, 5000 and 25000 T. spiralis spiralis infective larvae respectively by stomach tube. A predilection site of infection in all ponies was the tongue. Anti-Trichinella antibodies were detected in all ponies by the enzyme-linked immunosorbent assay using a T. spiralis spiralis excretory-secretory antigen. The ponies given 5000 and 25000 infective larvae reacted positively on days 26 and 24 postinfection, respectively, using a criterion of greater than or equal to 5 X mean optical density readings of preinfection sera as positive. The pony given 1000 larvae did not react positively although antibodies were present as indicated by 3 X to 4 X mean optical density readings of preinfection sera. The results of this limited study indicate that the enzyme-linked immunosorbent assay cannot be used to certify horsemeat free of Trichinella since the presence of detectable antibody levels appears to be related to the magnitude of the infection and duration of the infection when the animal is tested.  相似文献   

17.
The immune protective response developed by swine against Trichinella spiralis is not yet fully understood, particularly at the mucosal level. This study aimed to characterise intestinal immunity to T. spiralis by comparison with the systemic response in specifically pathogen-free pigs. For this purpose, the kinetics of cytokine and antibody production were assessed in the intestinal mucosa and serum of swine infected with T. spiralis for up to 60 days post-infection (dpi). An ex vivo model of jejunum mucosa culture was used to collect the supernatant as a source of antibodies (Abs). Mucosal antibodies were observed by Western blot from 15 dpi, while serum antibodies were expressed from 20 dpi. Both sources of antibodies initially recognized a 110 kDa protein, followed by the identification of 35, 43/46 and 55/59 kDa proteins. IgG1 and IgA antibodies were strongly expressed within the mucosa. The expression levels of Type 1 (IFN-gamma, IL-12), Type 2 (IL-4, IL-6), pro-inflammatory (TNF-alpha) and regulatory (IL-10, TGF-beta) cytokines were assessed by RT-PCR in the intestinal mucosa and spleen. Both IL-10 and IFN-gamma mRNA levels were increased in mucosa, whereas IL-6 and IL-12 mRNA were expressed in spleen. Taken together, these results demonstrated a mixed Type 1/Type 2 profile, the Type 2 profile being dominant in the mucosa.  相似文献   

18.
An ELISA using a Trichinella spiralis spiralis excretory-secretory antigen was evaluated as a procedure for the diagnosis of trichinosis in swine in Canada. Field and experimental trials were carried out using both indirect serological (ELISA) and direct parasitological (pepsin-digestion) methods concurrently on serum and musculature, respectively, from each animal. The ELISA is a sensitive and specific test for the detection of Trichinella antibodies in porcine sera when present. The development of Trichinella antibodies appears to be dependent on the magnitude of the infection established, age of the infection when the animal is tested and the immunocompetence or response to infection of individual animals. False negative reactions were recorded in both field and experimental trials. In the field study, five of the 1009 swine examined were parasitologically positive with light infections ranging from 0.01 to 0.046 larvae per gram (la/g) of musculature yet all were serologically negative. Experimentally it was shown that Trichinella antibodies develop slowly, at least two to three months postinfection, in pigs with very light infections. Even in pigs which developed infections of 33 to 55 la/g of musculature, seroconversion occurred greater than 23 and less than 30 days postinfection. The immunocompetence or response to infection of individual pigs was variable as illustrated by one pig inoculated with 3000 infective larvae which had consistently lower titers compared to others in the same group despite the establishment of a muscle infection of 8.5 la/g of musculature. One false positive reaction was recorded in the experimental trial in an animal which had received 100 larvae and seroconverted at about three months postinfection.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

19.
The ability of Trichinella spiralis larvae to survive at subfreezing temperatures encysted in the musculature of wild carnivorous mammals was assessed by evaluating motility and infectivity (to rodents) of trichinae at various intervals after storage in frozen skeletal muscle. Fifty to 60% of the larvae in grizzly bear meat were alive after storage for 27 months at -6.5 to -20 C, and 30% to 50% were still alive at 34 months. However, none survived for 38 months, on the basis of infectivity in mice and larval motility. Trichinella larvae survived up to 4 months in frozen (-6.5 to -20 C) wolverine tissue. Viable larvae were not recovered from mountain lion or fisher muscle frozen for 1 month. The effect of postslaughter processing on Trichinella larvae encysted in bear meat was evaluated by use of a similar bioassay procedure. Viability of larvae recovered from black bear meat that had been processed into ham or jerky was not affected by dry curing with a commercial salt mixture. Trichinae from both preparations induced infections in mice (58 to 90 larvae/g of tissue). However, a combination of curing and smoking was consistently lethal to encysted larvae. Viable trichinae were not recovered from ground bear meat preparations (pepperoni, salami, or sausage) processed according to commercial standards.  相似文献   

20.
ABSTRACT: Domestic pigs are the main representatives of the domestic cycle of Trichinella spiralis that play a role in transmission to humans. In Europe, backyard pigs of small household farms are the most important risks for humans to obtain trichinellosis. Rats might play a role in the transmission of Trichinella spiralis from domestic to sylvatic animals and vice versa. In order to be able to investigate the role of wild rats in the epidemiology of T. spiralis in The Netherlands, we studied the dynamics of antibody response after T. spiralis infections in experimental rats, using infection doses ranging from very low (10 muscle larvae, ML, per rat) to very high (16 000 ML per rat). To evaluate the feasibility of rats surviving high infection doses with T. spiralis, clinical and pathological parameters were quantified. Serological tools for detecting T. spiralis in rats were developed to quantitatively study the correlation between parasite load and immunological response. The results show that an infection dose-dependent antibody response was developed in rats after infection with as low as 10 ML up to a level of 10 000 ML. A positive correlation was found between the number of recovered ML and serum antibody levels, although specific measured antibody levels correspond to a wide range of LPG values. Serum antibodies of rats that were infected even with 10 or 25 ML could readily be detected by use of the T. spiralis western blot 2 weeks post infection. We conclude that based on these low infection doses, serologic tests are a useful tool to survey T. spiralis in wild rats.  相似文献   

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