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1.
Pregnant goats were inoculated intravenously or in uterine arteries with Brucella abortus, and tissues from the uterus and placenta were examined by electron microscopy. Identification of B. abortus in placentae was with antibody-coated colloidal gold. B. abortus was first seen in phagosomes of erythrophagocytic trophoblasts and in the rough endoplasmic reticulum of chorioallantoic trophoblasts. Subsequently, trophoblast necrosis and ulceration of chorioallantoic membranes were present. Coincidently, B. abortus was present in the lumen of placental capillaries. In late stages of infection, placental vasculitis was present, and placentomal trophoblasts were separated from maternal syncytial epithelium. In lesions with vasculitis, large numbers of B. abortus were in connective tissue of chorionic villi. Within the placentome, trophoblasts that lined chorionic villi contained no intracellular bacteria and were separated from B. abortus by intact basement membranes. These results suggest that bacteremic B. abortus is endocytosed by erythrophagocytic trophoblasts and that B. abortus replicates in the rough endoplasmic reticulum of chorioallantoic trophoblasts. Replication of brucellae in trophoblastic rough endoplasmic reticulum is unique; we believe that B. abortus may utilize endoplasmic reticulum for synthesis and glycosylation of bacterial membrane proteins or that B. abortus catabolizes trophoblast secretory proteins.  相似文献   

2.
Encephalitozoon cuniculi causes severe diseases in blue fox puppies. When pregnant vixens are infected, parasites are transmitted over the placenta to the unborn that subsequently develop encephalitozoonosis. Adult foxes themselves do not have signs of disease, but show antibody titres to E. cuniculi. The purpose of the present study was to gain information on the immune response in adult foxes after experimental infection. Sixteen foxes were infected orally with E. cuniculi spores, eight of them twice and 28 days apart. The two groups of animals showed elevated serological values in both the carbon immunoassay and in the ELISA. Elevated serological levels were recorded up to 1 year after the infection took place. The control group (n=8) remained serologically negative throughout the trial. The results of the study showed that blue foxes could be seropositive for at least a year after oral infection with E. cuniculi.  相似文献   

3.
Immune response to Encephalitozoon cuniculi infection in laboratory mice.   总被引：1，自引：0，他引：1  
The study was performed to determine the immune response to Encephalitozoon cuniculi infection in immunocompetent mice during 120 days of experiment. Mice infected with E. cuniculi had an increased number of CD4+ T cells up to Day 20 post infection (p.i.), but counts of CD8+ T lymphocytes were significantly lower up to Day 90 p.i. in peripheral blood. Blood monocytes were significantly increased on the Day 60 and Day 120 of infection. A lack of significant decrease of CD4+ T cells may be considered as an important event in the immune response to E. cuniculi infection in immunocompetent mice.  相似文献   

4.
Encephalitozoon cuniculi is a microsporidial parasite, which has rarely been reported to cause placentitis in animals. A late-term aborted fetus and placenta from a Quarterhorse were presented to the Livestock Disease Diagnostic Center, University of Kentucky, for diagnostic examination. There was a necrotizing placentitis, with distension of many chorionic epithelial cells by intracytoplasmic vacuoles containing 1-2-microm-diameter, elongated, gram-positive organisms. The organisms were identified as E. cuniculi by electron microscopy and by polymerase chain reaction using primers to microsporidial ribosomal DNA. Joints of the fetus were swollen, with gross and microscopic lesions of synovitis; however, E. cuniculi DNA was not detected.  相似文献   

5.
A captive, adult male Goeldi's monkey (Callimico goeldii) (GM) presented in acute respiratory distress 4 yr after importation into the United States from Europe. Radiographs and echocardiogram were consistent with heart failure. The monkey died within 24 hr of presentation. Necropsy findings included multicentric arteritis and aortitis with aneurysm associated with microsporidian organisms morphologically consistent with Encephalitozoon species. Polymerase chain reaction confirmed organisms were Encephalitozoon cuniculi. Sequence analysis of amplicons generated by using primers specific for the polar tube protein of E. cuniculi determined the organism to be genotype II. An E. cuniculi serosurvey of potentially exposed conspecifics that represented approximately 40% of the captive GM population in the United States was conducted. Multiple individuals that had been imported from Europe with the individual of this report were seropositive via an immunofluorescent antibody assay for E. cuniculi. Multiple samples were available from 3 individuals that demonstrated a decrease in titer or reversion to seronegative status within 3 yr of initial positive status. All other GM were negative on serology. This case is unique in that the genotype identified (genotype II) was different than the genotype (genotype III) reported in other New World primate (NWP) species, the patterns of arteritis were different from the typical pattern of microsporidial vasculitis described in other species, and clinical disease was observed in an adult. Most reported cases of clinical disease secondary to E. cuniculi in NWP have been in neonates and juveniles.  相似文献   

6.
Pregnant goats were given Brucella abortus intravenously or in uterine arteries, and tissues from the uterus and placentae were examined at various post-inoculation intervals to study mechanisms of placental infection. Placentitis was present by 5 days post-inoculation and abortions occurred within 11 days. B. abortus was identified in placentae by light microscopy and immunoperoxidase techniques. B. abortus was first seen in erythrophagocytic trophoblasts of the placentome. Subsequently, high numbers of B. abortus were seen in periplacentomal chorioallantoic trophoblasts. Trophoblast necrosis, chorioallantoic ulceration, and large numbers of B. abortus in chorionic villi were present in later stages of infection. These results suggest that entry and replication of B. abortus in trophoblasts precede placentome and fetal infection and that trophoblasts are the source of B. abortus for these tissues. Experimental caprine brucellosis closely resembles bovine and ovine brucellosis and it provides a model to study the intracellular development of B. abortus in trophoblasts.  相似文献   

7.
The farmed blue fox (Alopex lagopus) is particularly susceptible to congenital infections of the microsporidian species Encephalitozoon cuniculi. This report is based on an outbreak of the disease in Finland with high mortality. Five pups (four males and one female) with prolonged disease were examined. The pups had moderate pathological alterations in the kidneys and mild lesions were found in the brains, hearts, salivary and prostatic glands. Diagnosis of E. cuniculi infection was made from serological tests (ELISA, CIA, IFAT), and by in vitro isolation of the parasite from the brain of all five pups investigated. The identity was confirmed by molecular means as E. cuniculi strain II ('mouse strain'). Novel histopathological lesions not described as yet in fox encephalitozoonosis are presented. These include cerebral infarction and necrotizing inflammation of the renal pelvis. The sources and mechanisms of spreading of E. cuniculi to blue foxes are discussed.  相似文献   

8.
Mammalian microsporidiosis   总被引：7，自引：0，他引：7  
The phylum Microspora contains a diverse group of single-celled, obligate intracellular protozoa sharing a unique organelle, the polar filament, and parasitizing a wide variety of invertebrate and vertebrate animals, including insects, fish, birds, and mammals. Encephalitozoon cuniculi is the classic microsporidial parasite of mammals, and encephalitozoonosis in rabbits and rodents has been and continues to be recognized as a confounding variable in animal-based biomedical research. Although contemporary research colonies are screened for infection with this parasite, E. cuniculi remains a cause of morbidity and mortality in pet and conventionally raised rabbits. In addition, E. cuniculi is a potential pathogen of immature domestic dogs and farm-raised foxes. The recent discovery and identification of Encephalitozoon intestinalis, Encephalitozoon hellem, and Enterocytozoon bieneusi, in addition to E. cuniculi, as opportunistic pathogens of humans have renewed interest in the Microspora. Veterinary pathologists, trained in the comparative anatomy of multiple animal species and infectious disease processes, are in a unique position to contribute to the diagnosis and knowledge of the pathogenesis of these parasitic diseases. This review article covers the life cycle, ultrastructure, and biology of mammalian microsporaidia and the clinical disease and lesions seen in laboratory and domestic animals, particularly as they relate to Encephalitozoon species. Human microsporidial disease and animal models of human infection are also addressed. Often thought of as rabbit pathogens of historical importance, E. cuniculi and the related mammalian microsporidia are emerging as significant opportunistic pathogens of immunocompromised individuals.  相似文献   

9.
Kidney disease is a common and serious condition in domestic cats. There are numerous causes of kidney disease including parasitic infection. Encephalitozoon cuniculi is a microsporidian parasite that develops in the kidneys of rabbits and causes chronic renal disease. Little has been reported concerning E. cuniculi in cats and no serological studies on this parasite in cats have been conducted in the United States to date. The present study explored the possibility that E. cuniculi is an unrecognized contributor to the high prevalence of kidney disease observed in cats. A serological survey was conducted to determine the prevalence of IgG antibodies to spores of E. cuniculi in cats with and without a diagnosis of chronic kidney disease (CKD) according to the International Renal Interest Society (IRIS) staging system. Likewise, samples were examined for IgG antibodies to Toxoplasma gondii, a common well studied protozoan of cats. Plasma and sera were obtained from 232 feline patients at the Virginia-Maryland Regional College of Veterinary Medicine teaching hospital. With the investigators blinded to the renal status of test subjects, samples were screened via indirect immunofluorescent antibody assay (IFA). Thirty-six of the 232 cats met the IRIS staging system criteria for CKD. Antibodies to E. cuniculi were found in 15 of the 232 samples, which included 4 of the 36 cats with CKD. Sera from cats serologically positive to E. cuniculi did not react to spores of E. intestinalis or E. hellem when examined in the IFA. Antibodies to T. gondii were found in 63 of the 232 samples, which included 10 of the 36 cats with CKD. The prevalence of antibodies in cats with CKD to either protozoan was not significantly different (P>0.05) from the cats without CKD in the study. Collectively the results do not support the hypothesis that either E. cuniculi or T. gondii play a significant etiologic role in the occurrence or progression of CKD in cats.  相似文献   

10.
Microsporidia (Encephalitozoon cuniculi) in wild rabbits in Australia   总被引：1，自引：0，他引：1  
Objective To determine the prevalence of infection with Encephalitozoon cuniculi i n wild rabbit populations in Western Australia, and to isolate the organism from seropositive rabbits.
Design Serological screening of wild and clinically affected domestic rabbit populations.
Sample population Eighty-one wild rabbits from southwestern Western Australia and 29 laboratory rabbits.
Procedure Indirect immunofluorescence antibody technique and in-vitro amplification of parasite isolates in fibroblast cultures.
Results Of the 81 wild rabbits and 29 laboratory rabbits, 20 and 22 respectively, had antibodies to E cuniculi . E cuniculi from the urine of one seropositive laboratory rabbit and from brain and kidney tissues of eight and five seropositive laboratory and wild rabbits respectively were isolated in fibroblast cultures.
Conclusion E cuniculi infection has been shown for the first time to be prevalent in wild rabbits in Australia. Techniques have been developed for the isolation and culture of the causative agent. Comparative studies can now be undertaken to determine risk factors for clinical disease in domestic rabbits and the relationship among E cuniculi isolates from wild and domestic rabbits.  相似文献   

11.
To determine the occurrence of potentially human pathogenic microsporidia (Enterocytozoon bieneusi and Encephalitozoon spp.) in wild mice, we examined 289 East-European House Mice (Mus musculus musculus) and West-European House Mice (M. m. domesticus) trapped at 74 localities in an area across the Czech-German border. Microsporidia were detected at 33 localities, in 34% of M. m. musculus and 33% of M. m. domesticus examined specimens. Single-species infection was detected in 23 mice for E. hellem, 42 mice for E. cuniculi and 25 mice for E. bieneusi. No Encephalitozoon intestinalis positive animals were identified. Moreover, co-infections were detected in 6 animals; E. bieneusi co-existed with E. cuniculi or E. hellem in 3 mice. The natural infection of E. hellem has never been recorded in mice before. No differences were found by a statistical analysis of microsporidia occurrence between the House Mouse subspecies. Although the gender-dependent infestation of microsporidia was statistically supported in M. m. musculus, no significant differences were observed when the occurrence of microsporidia was estimated for all males and females irrespective of the House Mouse subspecies. The results of this report document the low host specificity of detected microsporidia species and imply the importance of synanthropic rodents as a potential source of human microsporidial infection.  相似文献   

12.
An ELISA, using Encephalitozoon cuniculi spores as antigen, was used to determine the prevalence of specific anti-E cuniculi IgG in a group of stray dogs. In a preliminary survey 51 of 248 sera were classified as positive with titres of 1:400 to 1:3200. The 18 sera with titres of 1:400 were reclassified as negative when no IgG binding to the spores could be detected by comparison with a standard curve of anti-E cuniculi IgG. The remaining 33 sera (13.3 per cent) were classified as low, moderate or strong positives. Comparison of total IgG and specific IgG showed that specific IgG was greatly increased in the moderately and strongly positive sera. E cuniculi may be of importance as one cause of fading puppy syndrome when transmitted transplacentally, and as a complicating infection in human immunodeficiency diseases.  相似文献   

13.
Inoculations of vixens with Encephalitozoon cuniculi (E. cuniculi), performed orally, either before or in the gestation period, or directly into the uterus at oestrus, induced clinical encephalitozoonosis in the offspring. The infection of the vixens, indicated by a general E. cuniculi antibody response, appeared to run a subclinical course. Endometritis was detected in some of the vixens when examined at the end of the trial. A temporary increase of total protein, albumin and globulin in the inoculated vixens compared to the controls was detected in the final 2 weeks of the gestation, concomitantly with the rise in humoral E. cuniculi antibody titres. The antibody levels appeared significantly higher in the group of vixens inoculated directly into the uterus than in the orally inoculated groups. Vixens exposed to the parasite seemed to possess a certain degree of acquired resistance to re-infection with the parasite when exposed in the following breeding season.  相似文献   

14.
Several indicators of immune response were observed in immunocompetent mice of the ICR line and those suppressed by dexamethasone upon their experimental infection with the microsporidia of Encephalitozoon cuniculi. The mice were infected by one-shot intraperitoneal administration of 5 x 10(7) pathogenic spores. On Days 7, 14, 28 and 42 after infection, peripheral blood leukocyte phagocytic activity was determined and compared, including phagocytic index and the blastogenic response in spleen cells to mitogenic activation by concanavalin A and phytohaemagglutinin. The results point to the fact that E. cuniculi itself can cause a significant decrease in phagocytic activity of phagocytic leukocytes in the early stages of infection as well as a remarkable decrease in the proliferative response of spleen cells to T-cellular mitogens.  相似文献   

15.
Encephalitozoon cuniculi is a small protist parasite in the phylum Microspora. Hosts are infected by ingestion or inhalation of spores passed in the urine or feces. Infection with E. cuniculi is usually asymptomatic, except in young or immunocompromised hosts. This study examined the effects of various disinfectants on in vitro infectivity of E. cuniculi spores. Spores of E. cuniculi were exposed to several dilutions of commercial bleach, 70% ethanol and dilutions of commercial disinfectants HiTor and Roccal for 10 min and then loaded onto human fibroblast cells (Hs68 cells). Ten minutes of exposure to these disinfectants was lethal to E. cuniculi spores. Additional exposure time studies were done using dilutions of bleach at 0.1, 1 and 10%, and 70% ethanol. Exposure of E. cuniculi spores to 1 or 10% bleach for 30s rendered them non-infectious for Hs68 cells. Growth of E. cuniculi was observed in Hs68 cells inoculated with spores treated with 0.1% bleach for 30s or 1, 3 and 5 min, but not with spores treated for 7 min or longer. Exposure of E. cuniculi spores to 70% ethanol for 30s rendered them non-infectious for Hs68 cells. Spores of E. cuniculi are more sensitive to disinfectants than are coccidial oocysts and other parasite cysts. The relatively short contact time needed to kill spores indicates that disinfection of animal housing may be a viable means to reduce exposure of animals to E. cuniculi spores.  相似文献   

16.
Newborn and young pups up to the age of 15 days were exposed to E. cuniculi, either by keeping the pups in cages together with orally inoculated foster-mothers and their offspring, or by oral inoculation with E. cuniculi spores. A majority of pups appeared sero-positive to E. cuniculi with the india-ink immuno-reaction from 35 to 87 days post exposure; spores of E. cuniculi were detected in organs of some of the animals. The non-inoculated pups kept together with the orally inoculated pups became seropositive from 49 to 129 days after the oral inoculations. However, the exposure of newborn and young pups failed to induce clinical encephalitozoo-nosis, and when killed at the time of pelting the body weights and fur quality appeared to be within the normal range in all exposed foxes. No macroscopic lesions were detected in the various organs. Histologically focal interstitial nephritis occurred in the great majority of the seropositive animals. Meningoencephalitis was seen in some of the foxes, whereas slightly thickened walls of some arteries, mainly in the myocardium, were found in a few animals. The lesions of the brain and kidneys seem to be very similar to those seen in chronic cases of rabbit encephalitozoonosis. Polyarteritis nodosa and severe encephalitis and interstitial nephritis with extensive proliferations of plasma cells, which are almost constant findings in cases of clinically diseased foxes, were not detected in any of the subclinically infected animals. Various factors that might be of significance in the pathogenesis of the disease are discussed, and it is concluded that intrauterine infection of the pups via the transplacental route appears to be an essential supposition for the establishment of clinical fox encephalitozoonosis.  相似文献   

17.
Encephalitozoon cuniculi is a small protozoan parasite in the phylum Microspora. It has been shown to naturally infect several host species, including humans. Encephalitozoonosis is routinely diagnosed in vivo by serological examination or post mortem by histopathology. In a conventional rabbit colony, two animals suddenly showed clinical signs (torticollis and asthenia of limbs). Serum samples of these rabbits were seropositive for E. cuniculi after definitive diagnosis (Toxoplasma gondii and Listeria monocytogenes). The animals in the same breeding facility were also clinical examined, and the present study evaluated the prevalence of specific anti-E. cuniculi antibodies using serological testing, both in animals and in people working with animals, after two clinical cases. The rabbits showed no clinical symptoms of the disease. Blood samples were taken for E. cuniculi infection from 50 clinically healthy rabbits. Anti-E. cuniculi antibodies were found in two asymptomatic and two clinically affected animals belonging to the same rabbit colony. Finally, the present study found that the 7.7% (4/52) prevalence of CIA, test positive in rabbits. E. cuniculi spores were detected in the urine of one clinically affected rabbit, and one seropositive animal caretaker after staining with the modified trichrome stain. In conclusion, the presence of seropositive, but apparently healthy rabbits indicates the need for screening examinations to detect the anti-E. cuniculi antibody in rabbits, especially considering the potential zoonotic risk. Therefore, persons should avoid contact with the urine of infected or healthy animals, and always use good personal hygiene when handling animals.  相似文献   

18.
This case report describes tuberculosis (TB) due to infection with Mycobacterium bovis (M. bovis) in alpaca (Lama pacos) on a farm in Ireland. Two severely debilitated alpaca were presented to the University Veterinary Hospital, University College Dublin in November 2004. Bloods were taken, and haematology and biochemistry results were indicative of chronic infection. Radiological examination showed evidence of diffuse granulomatous pneumonia suggestive of tuberculosis. On necropsy there were granulomatous lesions present throughout many body organs including lung, liver, kidney, intestine as well on peritoneum and mesentery. Culture of acid-fast bacilli from lesions led to a diagnosis of tuberculosis due to M. bovis. The use of intradermal skin testing proved inefficient and unreliable for ante mortem diagnosis of tuberculosis in alpaca. Infection due to M. bovis should be considered among the differential diagnoses of debilitating diseases in alpaca, particularly those farmed in areas known to be traditional black spots for tuberculosis in cattle.  相似文献   

19.
Microsporidia have been recognized recently as opportunistic pathogens in acquired immunodeficiency syndrome patients. In an attempt to develop an animal model of enteric microsporidiosis, adult (5 to 6 months old) male Flemish Giant rabbits from a closed New York colony were administered 5 x 10(3), 5 x 10(5), and 5 x 10(7) Encephalitozoon cuniculi per rectum. Rabbits given 5 x 10(5) and 5 x 10(7) E. cuniculi had moderate granulomatous periportal infiltrates, characterized by the presence of numerous macrophages, epithelioid cells and a few multinucleated giant cells, lymphocytes, and plasma cells. Inflammatory cells also were seen infiltrating the tunica adventitia and tunica media of hepatic portal veins and branches of the hepatic artery. This study demonstrates that administration of E. cuniculi per rectum to rabbits results in infection that is characterized by high frequency and severity of hepatic lesions.  相似文献   

20.
Channel catfish Ictalurus punctatus from a commercial farming operation in the Mississippi Delta were submitted for examination for the presence of infection by the trematode Bolbophorus damnificus. The fish were instead found to possess skin nodules suggestive of Henneguya pellis, a species previously described in the blue catfish I. furcatus. Despite the dermal location and distribution of lesions, morphological characteristics of the myxospores were inconsistent with H. pellis. Spores possessed a lanceolate spore body 15.4 +/- 1.5 microm (mean +/- SD; range = 12.2-19.3 microm) in length and 5.5 +/- 0.6 microm (range = 4.5-6.8 microm) in width in valvular view, and 4.7 +/- 0.2 microm (range = 4.2-5.0 microm) in width in sutural view. Polar capsules were pyriform and unequal in both length and width and contained polar filaments with six coils. Polar capsules measured 6.1 +/- 0.8 microm (range = 4.0-7.9 microm) long and 1.7 +/- 0.3 microm (range = 1.0-2.2 microm) wide. The caudal appendages were 50.5 +/- 8.3 microm (range = 34.8-71.4 micorm) long and the total length of the spore was 65.9 +/- 8.6 microm (range = 48.2-90.0 microm). The "blister like" plasmodia were round or ovoid, up to 2 mm in diameter, and randomly distributed throughout the epidermis of the fish. Histologically, plasmodia were confined to the dermis and elicited no inflammatory reaction from the fish. A blast search of the 18S small subunit rDNA sequence obtained by polymerase chain reaction amplification resulted in no identical sequence matches but indicated a close relationship to H. gurlei, H. ictaluri, and H. exilis. The unique host record, spore morphology, and novel genetic sequence derived from this isolate lead us to propose this isolate as a novel species, H. sutherlandi.  相似文献   

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