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1.
弓形虫是一种重要的机会性寄生原虫,可感染人、哺乳动物及鸟类,引起人兽共患弓形虫病。目前,弓形虫感染已经成为一种严重的、全球性的公共卫生安全问题,引起了医学界的广泛关注。肿瘤患者的机体存在免疫功能障碍,对其进行放疗或化疗的过程中,则会进一步的降低肿瘤患者的免疫功能,临床上因抗肿瘤治疗而引起的弓形虫为典型代表的难治愈性寄生虫病的重症化已经愈发明显。肿瘤患者合并弓形虫感染的相关研究逐渐成为弓形虫病研究热点。论文对我国肿瘤患者弓形虫的流行情况﹑基因分型﹑传播途径及防治措施做一概述,旨在为有效防控肿瘤患者弓形虫共感染提供参考。 相似文献
2.
Infection by Toxoplasma gondii is very common in cats although most remain disease free. The factors that trigger development of uveitis in some cats infected with T gondii have not been elucidated, but infection by more than one organism may be contributory. In this study, cats chronically infected with T gondii were inoculated with Bartonella henselae followed by FHV-1 to test the hypothesis that immune stimulation by multiple infections will reactivate ocular toxoplasmosis. Anterior uveitis and chorioretinitis were not detected in the cats with chronic T gondii infection thus allowing rejection of the hypothesis using this experimental design. 相似文献
3.
Portes Jde A Netto CD da Silva AJ Costa PR DaMatta RA dos Santos TA De Souza W Seabra SH 《Veterinary parasitology》2012,186(3-4):261-269
Toxoplasma gondii, the agent of Toxoplasmosis, is an obligate intracellular protozoan able to infect a wide range of vertebrate cells, including nonprofessional and professional phagocytes. Therefore, drugs must have intracellular activities in order to control this parasite. The most common therapy for Toxoplasmosis is the combination of sulfadiazine and pyrimethamine. This treatment is associated with adverse reactions, thus, the development of new drugs is necessary. In previous studies, naphthoquinone derivatives showed anti-cancer activity functioning as agents capable of acting on groups of DNA, preventing cancer cells duplication. These derivatives also display anti-parasitic activity against Plasmodium falciparum and Leishmania amazonensis. The derivative pterocarpanquinone tested in this work resulted from the molecular hybridization between pterocarpans and naphtoquinone that presents anti-tumoral and anti-parasitic activities of lapachol. The aim of this work was to determine if this derivative is able to change T. gondii growth within LLC-MK2 cells. The drug did not arrest host cell growth, but was able to decrease the infection index of T. gondii with an IC(50) of 2.5 μM. Scanning and transmission electron microscopy analysis showed morphological changes of parasites including membrane damage. The parasite that survived tended to encyst as seen by Dolichos biflorus lectin staining and Bag-1 expression. These results suggest that pterocarpanquinones are drugs potentially important for the killing and encystment of T. gondii. 相似文献
4.
Diagnosis of transplacentally induced toxoplasmosis in pigs 总被引：1，自引：0，他引：1
Seventeen sows were fed 1,000 Toxoplasma gondii oocysts of isolates GT-1 or PT-1 at 32 to 92 days of gestation, and the products of conception were examined for T gondii antibodies and parasites. Twelve of these sows were euthanatized near term between 21 and 62 days after being fed T gondii; fetal body fluids or fetal sera were examined for agglutinating T gondii antibodies, and tissues were bioassayed in mice for T gondii parasites. Six sows produced pigs that had been transplacentally infected with T gondii; one of them aborted a T gondii-infected fetus 17 days after ingesting oocytes. Agglutinating antibodies were detected in fetuses infected in utero, but transplacental transfer of T gondii antibodies was not observed in noninfected fetuses. Transcolostrally acquired T gondii antibodies disappeared by 3 months of age. Diagnosis of transplacental toxoplasmosis was confirmed on the basis of detection of T gondii organisms in fetal tissues by use of histologic examination and bioassay in mice. In conclusion, finding of T gondii antibodies in body fluids could serve as a rapid screening test for transplacental T gondii infection in pigs. 相似文献
5.
I Esteban-Redondo S W Maley K Thomson S Nicoll S Wright D Buxton E A Innes 《Veterinary parasitology》1999,86(3):155-171
It has been reported in the literature that cattle are more resistant to toxoplasmosis than sheep. Congenital disease due to T. gondii infection is rarely reported in cattle whereas the parasite is a major cause of abortion and neonatal mortality in sheep. It is believed that sheep remain chronically infected for life. Undercooked meat from infected sheep is an important source of infection for man. In contrast cattle are thought to harbour fewer parasite tissue cysts which may not persist for the lifetime of the host. Therefore, cattle are believed to pose less of a risk for human infection. In this study we examined the presence of T. gondii within a range of tissues in sheep and cattle at 6 weeks and 6 months following oral infection with 10(3) or 10(5) sporulated oocysts of T. gondii. The presence of parasite was determined by bioassay in mice and using polymerase chain reaction (PCR). The results from this study show that T. gondii was more frequently and consistently detected in sheep, in particular within brain and heart tissues, whereas parasites were not detected in the samples of tissues taken from cattle. T. gondii was more frequently detected in sheep given the higher dose of T. gondii. Examination of tissues at either 6 weeks or 6 months after infection did not appear to affect the distribution of T. gondii. The polymerase chain reaction has more specificity and sensitivity when detecting the presence of T. gondii in large animals than histological detection. 相似文献
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7.
Brown hares (Lepus europaeus) trapped in the countryside and domestic rabbits were experimentally infected with Toxoplasma gondii (K7 strain) oocysts. Hares (n=12) were divided into groups of 4 and infected with 10, 10(3) and 10(5) oocysts. Rabbits (n=12) were infected in the same way. The experimentally infected animals were monitored for 33 days after infection (p.i.). Most of the infected hares demonstrated behavioural changes, and all of them died between 8 and 19 days p.i. Three of the rabbits demonstrated only clinical changes related to the concurrent pasteurellosis. The typical pathological finding in the hares were haemorrhagic enteritis, enlargement and hyperaemia of mesenteric lymph nodes, splenomegaly and multiple miliary necrotic lesions in the parenchyma of the liver and other organs. Pathological changes in the rabbits were less pronounced than in the hares. In rabbit brains, tissue cysts of the T. gondii were found. The incidence of T. gondii antibodies both in the hares and the rabbits was first ascertained on day 7 p.i. On day 12 p.i., antibodies were already found in all the animals infected. Antibody titres in indirect fluorescence antibody test (IFAT) using the anti-rabbit conjugate were markedly higher in rabbits than in hares. In all hares, T. gondii was isolated post mortem from the liver, brain, spleen, kidney, lung, heart and skeletal muscles. Although T. gondii was also isolated in all rabbits, it was not always isolated in all their organs. In all hares, parasitemia was demonstrated on days 7 and 12 p.i. The percentage of rabbits with detected parasitemia was lower. In hares, a decrease in the numbers of leukocytes during the infection was observed. No such decrease was observed in the rabbits. The lymphocyte activity after the stimulation with non-specific mitogens showed significant differences between the hares and the rabbits even before the infection. After the infection, the hares infected with 10(3) and 10(5) doses and in rabbits infected with a 10(5) dose showed a decrease of lymphocyte activity. Rabbits infected with a 10(3) dose showed an increase of the lymphocyte activity. While in hares toxoplasmosis was an acute and fatal disease, the infection in rabbits had subclinical manifestations only and easily passed to a latent stage. The different courses of toxoplasmosis in the hare and the rabbit may be due to the differences in the natural sensitivity of the two species to the T. gondii infection or a negative impact of stress to the immune status of hares. 相似文献
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9.
J P Dubey 《Veterinary parasitology》1986,22(3-4):177-202
Worldwide reports of natural and experimentally-induced Toxoplasma gondii infections in cattle are reviewed and tabulated. Serologic tests employed in most studies in the past are of suboptimal sensitivity for the diagnosis of T. gondii infection in cattle; therefore data need to be interpreted with caution. From the evidence available it is concluded that: T. gondii is probably not important in causing abortion or clinical illness in cattle but further experimental studies are desirable; T. gondii is eliminated quickly from bovine tissues; Whether beef plays a part in the epidemiology of toxoplasmosis is unresolved; Milk from T. gondii-infected cows is of negligible importance in the epidemiology of toxoplasmosis. 相似文献
10.
Bowater RO Norton J Johnson S Hill B O'Donoghue P Prior H 《Australian veterinary journal》2003,81(10):627-632
OBJECTIVE: To describe the clinical signs, gross pathology, serology, bacteriology, histopathology, electron microscopy and immunohistochemistry findings associated with toxoplasmosis in four Indo-Pacific humpbacked dolphins (Sousa chinensis) that stranded in Queensland in 2000 and 2001. DESIGN: Clinical assessment, gross necropsy, and laboratory examinations. PROCEDURE: Necropsies were performed on four S. chinensis to determine cause of death. Laboratory tests including serology, bacteriology, histopathology and transmission electron microscopy were done on the four dolphins. Immunohistochemistry was done on the brain, heart, liver, lung, spleen and adrenal gland from various dolphins to detect Toxoplasma gondii antigens. RESULTS: Necropsies showed all of four S. chinensis that stranded in Queensland in 2000 and 2001 had evidence of predatory shark attack and three were extremely emaciated. Histopathological examinations showed all four dolphins had toxoplasmosis with tissue cysts resembling T. gondii in the brain. Tachyzoite stages of T. gondii were detected in the lungs, heart, liver, spleen and adrenal gland, variously of all four dolphins. Electron microscopy studies and immunohistochemistry confirmed the tissues cysts were those of T. gondii. All four dolphins also had intercurrent disease including pneumonia, three had peritonitis and one had pancreatitis. CONCLUSION: Four S. chinensis necropsied in Queensland in 2000 and 2001 were found to be infected with toxoplasmosis. It is uncertain how these dolphins became infected and further studies are needed to determine how S. chinensis acquire toxoplasmosis. All four dolphins stranded after periods of heavy rainfall, and coastal freshwater runoff may be a risk factor for T. gondii infection in S. chinensis. This disease should be of concern to wildlife managers since S. chinensis is a rare species and its numbers appear to be declining. 相似文献
11.
Michael R. Lappin DVM PhD Amanda Marks MS Craig E. Greene DVM MS Barbara J. Rose MT Peter W. Gasper DVM PhD Cynthia C. Powell DVM MS John S. Reif DVM 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1993,7(2):95-100
Serum samples from 89 cats with serologic evidence of toxoplasmosis were identified by using an enzyme-linked immunosorbent assay (ELISA) that detected Toxoplasma gondii -specific immunoglobulin M (IgM) or T. gondii -specific immunoglobulin G (IgG). Concurrent feline immunodeficiency virus (FIV) infection was detected in 36 cats using an ELISA for detection of FIV-specific IgG. The majority of the cats in both the FIV-seropositive and FIV-seronegative groups were male and >5 years of age. FIV-seropositive cats were more likely to have T. gondii IgM titers without IgG ( P > 0.05) or any T. gondii IgM titer ( P > 0.05) than were FIV-seronegative cats. FIV-seronegative cats (1328) had a higher T. gondii IgG geometric mean titer than did FIV-seropositive cats (724) and were more likely to have T. gondii IgG titers 1:2048 than were FIV-seropositive cats ( P > 0.05). Cats with serologic evidence of both T. gondii and FIV infections had persistent T. gondii IgM titers for >12 weeks. Lymphoblast transformation in response to concanavalin A, T. gondii -specific intracellular antigens, and T. gondii -specific secretory antigens was compared in T. gondii seropositive and FIV-seronegative cats, cats with serologic evidence of T. gondii infection alone, and cats with serologic evidence of concurrent FIV and T. gondii infections. Lymphocytes from all but one cat in the FIV-seropositive group responded to concanavalin A. Whereas lymphocytes from FIV-seronegative cats with serologic evidence of toxoplasmosis responded to T. gondii -specific antigens, four of five of the FIV-seropositive cats with concurrent serologic evidence of toxoplasmosis did not. 相似文献
12.
Feline ocular toxoplasmosis 总被引：2，自引：0，他引：2
Ocular infection with Toxoplasma gondii is a well-recognized and important clinical entity in many animal species. In the cat, ocular toxoplasmosis is commonly associated with systemic infection, yet its role in causing anterior uveitis in an otherwise healthy cat is unclear. The purpose of this article is to review the salient epidemiological, clinical, and histopathologic features of systemic and ocular toxoplasmosis in the cat. Additionally, pathogenesis and possible immunopathogenic mechanisms of ocular toxoplasmosis, which may account for the higher prevalence of anterior uveitis in cats seropositive for T. gondii , are discussed. Finally, diagnosis, treatment and prevention of feline toxoplasmosis are reviewed. 相似文献
13.
Buxton D Maley SW Wright SE Rodger S Bartley P Innes EA 《Veterinary parasitology》2007,149(1-2):25-28
Ovine toxoplasmosis, caused by the intracellular protozoan parasite Toxoplasma gondii, was first described in 1954 and while the incidence of ovine infection is difficult to define, it has been reported that in the UK it is responsible for between 1 and 2% of neonatal losses per annum. Recent reports have suggested that sheep persistently infected with T. gondii may pass infection to the fetus in subsequent pregnancies more readily than previously thought. These data show a high proportion of both successful and failed pregnancies in sheep to be positive by PCR for T. gondii with a tendency for samples from certain genetic lines of Charollais sheep more likely to be positive than samples from other lines, suggesting that some sheep have a particular genetic susceptibility to T. gondii. 相似文献
14.
Basso W Venturini MC Moré G Quiroga A Bacigalupe D Unzaga JM Larsen A Laplace R Venturini L 《Veterinary parasitology》2007,144(1-2):157-161
Wallabies and other Australian marsupials are among the most susceptible species to Toxoplasma gondii. Fatal generalized toxoplasmosis was diagnosed in two captive 3 year-old female Bennett's wallabies (Macropus rufogriseus) from Argentina (w 1 and w 2) with a history of sudden death. Both animals had internal joeys which died 2 days after their mothers. Serologically, both females and one adult male without clinical signs from the same enclosure (w 3) had antibody titers for T. gondii>or=800 by the modified agglutination test (MAT); another adult male (w 4) was negative (MAT titer<25). Microscopically, tachyzoites were observed associated to non-suppurative meningoencephalitis, hepatitis, myositis, myocarditis and severe enteritis in hematoxylin and eosin stained sections from both w 1 and w 2. Immunohistochemically, parasites in heart, brain and liver sections of both female wallabies reacted with T. gondii antiserum. T. gondii was isolated from brain tissues of w 1 and w 2 by bioassay in mice and by culture in bovine monocytes and both isolates were cryopreserved. Genomic DNA was isolated from tachyzoites grown in cultures derived from both animals. The primer pair B22/B23 specific for T. gondii produced 115bp amplicons on poliacrylamide electrophoretic gels. Stray cats were suspected as the possible source of infection. Not all infected macropods were ill, showing that the infection may be asymptomatic and is not always fatal. A vertical infection could not be proved in the joey from w 2. As far as we know, this is the first confirmed report of toxoplasmosis in Bennet's wallabies in Argentina. 相似文献
15.
Toxoplasma gondii infection in marine mammals is important because they are considered as a sentinel for contamination of seas with T. gondii oocysts, and toxoplasmosis causes mortality in these animals, particularly sea otters. Serological evidence of T. gondii infection was determined in 75 captive marine mammals from four facilities in southern and central geographical regions in Mexico using the modified agglutination test (MAT). Antibodies (MAT, 1:25 or higher) to T. gondii were found in 55 (87.3%) of 63 Atlantic bottlenose dolphins (Tursiops truncatus truncatus), 3 of 3 Pacific bottlenose dolphins (Tursiops truncatus gillii), 2 of 4 California sea lions (Zalophus californianus), but not in 3 West Indian manatees (Trichechus manatus), and 2 Patagonian sea lions (Otaria flavescens). Seropositive marine mammals were found in all 4 (100%) facilities sampled. All marine mammals were healthy and there has not been any case of clinical toxoplasmosis in the facilities sampled for at least the last 15 years. The seroprevalence of T. gondii infection in marine mammals of the same species did not vary significantly with respect to sex and age. This is the first report on the detection of antibodies to T. gondii in marine mammals in Mexico. 相似文献
16.
Makala LH Reyes JC Nishikawa Y Tsushima Y Xuan X Huang X Nagasawa H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(5):591-597
A comparison of the expression of surface membrane antigens between dendritic cells (DC) derived from Peyer's patch macrophages (DPP-DC) of non-infected and Toxoplasma gondii (T. gondii) infected mice was performed. C57BL/6J mice aged 6-8 weeks of both sexes were infected orally with a 0.5 ml suspension containing 2 x 10(4) bradyzoites of the Beverley strain of T. gondii, sacrificed on day 8 and DC generated using discrete Peyer's patch macrophages (DPP-M?) as progenitor cells. When a comparison of the expression of surface membrane antigens between the antigen presenting cells (APC) obtained from discrete Peyer's patches of non-infected and T. gondii infected mice was carried out, no significant differences were observed in the macrophage progenitor and DC populations expression of F4/80, DEC-205, CD11c, CD80 (B7-1) and CD34. However, a significant decrease in MHC class II antigen levels and a down regulation of the co-stimulatory molecule CD86 (B7-2) were noted. B7-1 appeared to be the dominant co-stimulatory ligand, whereas B7-2, which was down regulated during T. gondii infection, had a weak expression. Taken together, these results may help clarify the role of DC in the complex network regulating surface membrane antigens, as well as, their capacity for antigen uptake, processing and presentation during toxoplasmosis. 相似文献
17.
The concentrations of enrofloxacin were measured in the tears, saliva and serum of 14 cats with signs of upper respiratory tract infection and eight with no signs, after daily doses of 5 mg/kg. Enrofloxacin concentrations above the minimum inhibitory concentration of Chlamydophila felis were found in the saliva and tears of the cats with and without signs of upper respiratory tract infection. In a prospective randomised clinical trial, the efficacy of enrofloxacin against C. felis infection in cats with conjunctivitis was compared with the efficacy of doxycycline. Twenty-five cats were randomly assigned to treatment with either enrofloxacin or doxycycline for 14 days; 15 of the cats tested positive for C. felis by an immunofluorescent antibody test on conjunctival swabs. The two treatment groups showed equal improvements in the clinical signs of conjunctivitis and C. felis infection status; in each group three cats were still C. felis antigen-positive after the 14-day course of treatment, indicating a persistent infection. No side effects were observed in the cats treated with enrofloxacin. 相似文献
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19.
J P Dubey 《American journal of veterinary research》1988,49(6):905-909
Fifteen pregnant does were inoculated orally with 10 to 1,000 oocysts of the GT-1 strain of Toxoplasma gondii. Two does were euthanatized on postinoculation days (PID) 10 and 14, and the remaining 13 does aborted or delivered kids transplacentally infected with T gondii on PID 9 to 65. Tissues of all 34 fetuses or kids from the inoculated does were examined for gross and microscopic lesions. Placental necrosis and encephalomyelitis were the most prominent lesions. Toxoplasma gondii invaded the fetal placenta between PID 9 and 11 and invaded fetal tissues 2 to 3 days later. Necrosis attributed to toxoplasmosis, confined to cotyledons, was found in all placentas examined on PID 18. Encephalomyelitis was found in most fetuses or kids between PID 30 and 65. Lesions in fetal tissues were sparse. Because T gondii is rarely found in lesions, histologic examination of the fetal tissues is not likely to help in diagnosing every case of transplacentally induced toxoplasmosis in goats. 相似文献
20.
Sós E Szigeti A Fok E Molnár V Erdélyi K Perge E Biksi I Gál J 《Acta veterinaria Hungarica》2012,60(3):361-370
Smaller macropodid species (commonly referred to as wallabies) are extremely susceptible to toxoplasmosis: in most cases, infection with Toxoplasma gondii leads to death within a short time. Between June 2006 and July 2010, T. gondii was detected by immunohistochemical examination in six Tammar wallabies (Macropus eugenii) that died in the Budapest Zoo and Botanical Garden; in another four specimens histopathology revealed T. gondii-like organisms (which could not be differentiated from Neospora caninum solely by morphology), and in another 11 animals toxoplasmosis as the possible cause of death could not be excluded. The current zoo population of 12 Tammar wallabies was tested for T. gondii IgG antibodies by the modified agglutination test (MAT), with negative results. We suppose that most of the deaths were due to acute toxoplasmosis resulting from a recent infection. 相似文献