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survival of toxoplasma gondii oocysts in eastern oysters (crassostrea virginica).toxoplasma gondii has recently been recognized to be widely prevalent in the marine environment. it has previously been determined that eastern oysters (crassostrea virginica) can remove sporulated t. gondii oocysts from seawater and that oocysts retain their infectivity for mice. this study examined the long-term survival of t. gondii oocysts in oysters and examined how efficient oysters were at removing oocysts from seawater. oysters in 76-l aquaria (15 oysters per aquarium) were exposed to 1 ...200415562605
biologic and molecular characteristics of toxoplasma gondii isolates from striped skunk (mephitis mephitis), canada goose (branta canadensis), black-winged lory (eos cyanogenia), and cats (felis catus).toxoplasma gondii isolates can be grouped into 3 genetic lineages. type i isolates are considered virulent to outbred mice, whereas type ii and iii isolates are not. in the present report, viable t. gondii was isolated for the first time from striped skunk (mephitis mephitis), canada goose (branta canadensis), and black-winged lory (eos cyanogenia). for the isolation of t. gondii, tissues were bioassayed in mice, and genotyping was based on the sag2 locus. toxoplasma gondii was isolated from 3 o ...200415562622
toxoplasmosis - a waterborne zoonosis.humans become infected with toxoplasma gondii mainly by ingesting uncooked meat containing viable tissue cysts or by ingesting food or water contaminated with oocysts from the feces of infected cats. circumstantial evidence suggests that oocyst-induced infections in humans are clinically more severe than tissue cyst-acquired infections. until recently, water-borne transmission of t. gondii was considered uncommon but a large human outbreak linked to contamination of a municipal water reservoir i ...200415567579
prevalence of antibodies to toxoplasma gondii and intestinal parasites in stray, farm and household cats in spain.seroprevalence of toxoplasma gondii was tested for in 585 cats in different regions of spain. sera were tested by the indirect immunofluorescence antibody test (ifat). specific antitoxoplasma igg (ifat titer>or=1/80) were found in 189 of 585 (32.3%): 117 of 317 (36.9%) stray cats, 16 of 48 (33.3%) farm cats and 56 of 220 (25.5%) household cats. the overall prevalence was significantly higher in stray groups (36.4% of 365) than in household cats (25.5% of 220), higher in adult cats (>6 months old ...200415567588
recent expansion of toxoplasma through enhanced oral transmission.the global predominance of three clonal toxoplasma gondii lineages suggests that they are endowed with an exceptional trait responsible for their current parasitism of nearly all warm-blooded vertebrates. genetic polymorphism analyses indicate that these clonal lineages emerged within the last 10,000 years after a single genetic cross. comparison with ancient strains (approximately 1 million years) suggests that the success of the clonal lineages resulted from the concurrent acquisition of direc ...200312532022
[serological survey of toxoplasma gondii infection in isolated amerindians, mato grosso].this study determined the occurrence of the antibodies anti-toxoplasma gondii among the enawenê-nawê, an indigenous population of mato grosso. these inhabit a vast wild area, with rare contacts with non-indians. they do not keep domestic animals, including cats. their diet is based on insects, cassava, corn, honey and mushrooms, they do not consume meat, except fish. based on the above, serologic tests elisa-igg and indirect fluorescent antibody test for igg/igm were performed. from 148 samples, ...200315049105
toxoplasma gondii and schizophrenia.recent epidemiologic studies indicate that infectious agents may contribute to some cases of schizophrenia. in animals, infections with toxoplasma gondii can alter behavior and neurotransmitter function. in humans, acute infection with t. gondii can produce psychotic symptoms similar to those displayed by persons with schizophrenia. since 1953, a total of 19 studies of t. gondii antibodies in persons with schizophrenia and other severe psychiatric disorders and in controls have been reported; 18 ...200314725265
genotyping of toxoplasma gondii isolates from chickens from india.the present study was undertaken to isolate and genotype toxoplasma gondii from free-range chickens (gallus domesticus) from villages in maharashtra and tamil nadu states of central and south india, respectively. blood, heart, and brain from a total of 741 chickens were examined for t. gondii infection. antibodies to t. gondii, as assayed with the modified agglutination test (mat >or = 1:5) were found in 133 (17.9%) chickens. hearts and brains of 186 chickens were bioassayed in mice. additionall ...200314729166
sporulation and survival of toxoplasma gondii oocysts in seawater.we have been collaborating since 1992 in studies on southern sea otters (enhydra lutris nereis) as part of a program to define factors, which may be responsible for limiting the growth of the southern sea otter population. we previously demonstrated toxoplasma gondii in sea otters. we postulated that cat feces containing oocysts could be entering the marine environment through storm run-off or through municipal sewage since cat feces are often disposed down toilets by cat owners. the present stu ...200314736220
seroprevalence of bartonella henselae, toxoplasma gondii, fiv and felv infections in domestic cats in japan.seroprevalence of bartonella henselae, toxoplasma gondii, feline immunodeficiency virus (fiv) and feline leukemia virus (felv) infections was investigated in 1,447 domestic cats derived from the north (hokkaido) to the south (okinawa) prefectures in japan. of the cats investigated, 8.8% (128/1,447) were seropositive to b. henselae, 5.4% (78/1,447) to t. gondii, 9.8% (107/1,088) to fiv, and 2.9% (32/1,088) to felv, respectively. for b. henselae infection, the positive rate varied from 11.5% in ca ...200312680718
toxoplasma gondii infection, atopy and autoimmune disease.while for many allergens a dose-response relationship has clearly been established the association between early childhood exposure to cat allergens and risk of sensitisation is still controversial and even inverse relations have been described. at the same time, a negative association between toxoplasma gondii (t. gondii) infection and atopic diseases has been found in epidemiologic studies. as cats are the major source of t. gondii oocysts, we hypothesize that cat allergen exposure might be a ...200312765860
seroprevalence of toxoplasma gondii infection among veterinary staff in ontario, canada (2002): implications for teratogenic risk.toxoplasma gondii infection is embryotoxic in humans. it is mainly transmitted through raw/undercooked meat and ingestion of oocysts in cat feces. there remains controversy about the actual risk of cats transmitting the disease to humans. our primary objective was to determine the seroprevalence of t. gondii antibody among veterinary staff, to ascertain whether they have an increased risk through occupational exposure. our secondary objective was to examine their practices regarding cats, toxopl ...200312769831
congenital toxoplasmosis.approximately 85 percent of women of childbearing age in the united states are susceptible to acute infection with the protozoan parasite toxoplasma gondii. transmission of t. gondii to the fetus can result in serious health problems, including mental retardation, seizures, blindness, and death. some health problems may not become apparent until the second or third decade of life. an estimated 400 to 4,000 cases of congenital toxoplasmosis occur in the united states each year. serologic tests ar ...200312776962
isolation and molecular characterization of toxoplasma gondii from chickens and ducks from egypt.the prevalence of toxoplasma gondii in free range chickens is a good indicator of the prevalence of t. gondii oocysts in the environment because chickens feed from the ground. in the present study, prevalence of t. gondii in 121 free range chickens (gallus domesticus) and 19 ducks (anas sp.) from a rural area surrounding giza, egypt was assessed. blood, heart, and brain from each animal were examined for t. gondii infection. antibodies to t. gondii, assayed with the modified agglutination test ( ...200312781471
transmission dynamics of toxoplasma gondii on a pig farm.transmission of toxoplasma gondii infection on a pig farm in new england was investigated using genetic and ecological methods to (i) determine if infection of pigs was a result of a single source, such as in an epizootic situation (e.g. outbreak) or of multiple sources, such as in an enzootic situation, (ii) identify the main source species of infection to pigs and (iii) evaluate the role of the environment surrounding the farm as the source of infection on the farm. genetic characterization of ...200312809808
[formation and diversity of parasitophorous vacuoles in parasitic protozoa. the coccidia (sporozoa, apicomplexa)].data on parasitophorous vacuole (pv) formation in host cells (hc) harbouring different intracellular protozoan parasites have been reviewed and critically analysed, with special reference to the main representatives of the coccidia. the vacuole membrane (pvm) is the interface between host and parasite, playing a role in nutrient acquisition by the parasite from the hc. the pv phenomenon is regarded as a generalized hc response to the introduction of alien bodies (microorganisms), which eventuall ...200314520865
development of a pcr-enzyme immunoassay oligoprobe detection method for toxoplasma gondii oocysts, incorporating pcr controls.infections caused by toxoplasma gondii are widely prevalent in animals and humans throughout the world. in the united states, an estimated 23% of adolescents and adults have laboratory evidence of t. gondii infection. t. gondii has been identified as a major opportunistic pathogen in immunocompromised individuals, in whom it can cause life-threatening disease. water contaminated with feces from domestic cats or other felids may be an important source of human exposure to t. gondii oocysts. becau ...200314532030
prevalence of antibodies to neospora caninum, sarcocystis neurona, and toxoplasma gondii in wild horses from central wyoming.sarcocystis neurona, neospora caninum, n. hughesi, and toxoplasma gondii are 4 related coccidians considered to be associated with encephalomyelitis in horses. the source of infection for n. hughesi is unknown, whereas opossums, dogs, and cats are the definitive hosts for s. neurona, n. caninum, and t. gondii, respectively. seroprevalence of these coccidians in 276 wild horses from central wyoming outside the known range of the opossum (didelphis virginiana) was determined. antibodies to t. gond ...200314533680
low virulence of oocysts of czech toxoplasma gondii isolates on the basis of biological and genetic characteristics.the virulence of the oocysts of 7 czech toxoplasma gondii isolates was tested. the oocysts were obtained by experimental infection of cats with the tissue cysts of t. gondii isolates from dogs, cats, and rabbits. the cats shed the oocysts in feces, with prepatent periods of 3-5 days postinfection (pi); the patent period was 7-18 days. the number of oocysts shed varied between 0.94 million and 47 million, with 0.66 million-39 million oocysts found in the daily samples of excrement. the cats cease ...200314533690
toxoplasma gondii isolates of free-ranging chickens from rio de janeiro, brazil: mouse mortality, genotype, and oocyst shedding by cats.most isolates of toxoplasma gondii can be grouped into 3 genetic lineages. in the present study, 67 isolates of t. gondii were obtained by bioassay in mice inoculated with brains and hearts of 96 asymptomatic chickens from an area highly endemic to human infection in rio de janeiro, brazil. of the 48 isolates genotyped using the sag2 locus, 34 (70%) were of type i and 13 (27%) were of type iii. no isolate of type ii was recovered. isolates from 1 chicken contained a type i and type iii mixed inf ...200314533703
autofluorescence of toxoplasma gondii and related coccidian oocysts.this is the first report of blue autofluorescence as a useful characteristic in the microscopic detection of toxoplasma gondii, hammondia hammondi, hammondia heydorni, neospora caninum, besnoitia darlingi, and sarcocystis neurona oocysts or sporocysts. this autofluorescence is of sufficient intensity and duration to allow identification of these oocysts from complex microscopic sample backgrounds. as with the autofluorescence of related coccidia, the oocysts glow pale blue when illuminated with ...200314533708
[parasitological risks--from animal husbandry to food and humans].livestock management influences the infection risk with parasites. extensive outdoor management increases the well being of the animals, but may also increase the infection risk with vector or intermediate host transmitted parasites. several parasites can be transmitted by food. trichinellosis again represents an increasing threat to human health by newly discovered species, new reservoir hosts and increasing meat import from eastern europe. tapeworm infections with taenia saginata are more freq ...200314535062
redescription of hammondia hammondi and its differentiation from toxoplasma gondii.hammondia hammondi is a protozoan parasite that, until 1975, was misidentified as toxoplasma gondii. recently, the validity of h. hammondi has been questioned. in this article, the authors redescribe the parasite and its life cycle, provide accession numbers to its specimens deposited in a museum, and distinguish it structurally and biologically from t. gondii. hammondia hammondi was found to be structurally, biologically, and molecularly different from t. gondii.200314572507
seroprevalence of neospora caninum and toxoplasma gondii in captive and free-ranging nondomestic felids in the united states.seven serum samples of 101 samples from nondomestic, captive and free-ranging felids from the united states were indirect fluorescent antibody positive for antibodies to neospora caninum, whereas 44 samples were positive for antibodies to t. gondii. although none of the captive animals displayed clinical signs of disease, nondomestic felids in the united states have been exposed to, and are likely infected with, n. caninum and t. gondii. this may have serious implications for zoological gardens ...200314582785
[identification of risk factors for infection with toxoplasma gondii in serbia as a basis of a program for prevention of congenital toxoplasmosis].toxoplasmosis has long been known as a major cause of perinatal morbidity. acute infection in pregnancy may lead to fetal infection and subsequent fetal loss or birth of a manifestly or latently infected infant. however, it is a preventable disease. in europe, significant variations have been shown to occur not only between countries but also within a given country indicating local variations in the influence of epidemiological factors contributing to infection. thus, many european countries hav ...200314608881
toxoplasma gondii isolates from free-ranging chickens from the united states.prevalence of toxoplasma gondii infection in chickens is a good indicator of the strains prevalent in their environment because they feed from ground. the prevalence of t. gondii was determined in 118 free-range chickens from 14 counties in ohio and in 11 chickens from a pig farm in massachusetts. toxoplasma gondii antibodies (> or = 1: 5) were found using the modified agglutination test (mat) in 20 of 118 chickens from ohio. viable t. gondii was recovered from 11 of 20 seropositive chickens by ...200314627158
seroprevalence of toxoplasma gondii antibodies in domestic cats from barcelona, spain.cats are important in the epidemiology of toxoplasma gondii infection because they are the only hosts that can excrete the environmentally resistant oocysts. antibodies to t. gondii were determined in serum samples from 220 domestic cats (felis catus) from barcelona, spain, using the modified agglutination test (mat). antibodies to t. gondii were found in 99 (45%) of 220 cats, with mat titers of 1:25 in 26, 1:50 in 57, and > or = 1:500 in 16 cats. seropositivity (mat 1:25 or more) was significan ...200314627161
characterization of toxoplasma gondii isolates from free range chickens from paraná, brazil.the prevalence of toxoplasma gondii in free range chickens is a good indicator of the prevalence of t. gondii oocysts in the environment because chickens feed from the ground. in the present study, prevalence of t. gondii in 40 free range chickens (gallus domesticus) from a rural area surrounding paraná, brazil was assessed. blood, heart, and brain from each chicken were examined for t. gondii infection. antibodies to t. gondii, assayed with the modified agglutination test (mat> or =1:5) were fo ...200314630431
use of a multiplex polymerase chain reaction assay in the antemortem diagnosis of toxoplasmosis and neosporosis in the central nervous system of cats and dogs.to develop a multiplex polymerase chain reaction (pcr) assay for the detection of toxoplasma gondii and neospora caninum dna in canine and feline biological samples. sample population; biological samples from 7 cats with systemic (n = 4) or cns (3) toxoplasmosis, 6 dogs with neospora- or toxoplasma-associated encephalitis, and 11 animals with nonprotozoal disease.200314672429
[cloning and expression of the signaling protein 14-3-3 of toxoplasma gondii].to clone and express the cell signaling protein 14-3-3 gene from toxoplasma gondii rh strain.200315108517
toxoplasma gondii antibody in thai cats and their owners.humans are thought to acquire toxoplasma infection by three major routes: ingesting food and water contaminated with oocysts from cat excreta, consumption of under-cooked infected meat, and transplacental transfer. congenital clinical toxoplasmosis in the newborn indicating definite transplacental transmission had been reported in thailand, whilst studies concerning infection due to the other two routes were inconclusive. since the way domestic cats live and eat and also the eating behavior of t ...200315115080
toxoplasmosis-related knowledge and practices among pregnant women in the united states.infection with toxoplasma gondii during pregnancy can lead to severe illness in the fetus. many t. gondii infections are preventable by simple hygienic measures.200315022874
mother-to-child transmission and diagnosis of toxoplasma gondii infection during pregnancy.toxoplasmosis is caused by a coccidian parasite toxoplasma gondii. it is world-wide in distribution and infects most of the vertebrates. the cat family animals (felides) are its definitive host. the humans are infected either through contaminated food, water, transfusion of infected blood, organ transplantation or from mother-to-foetus through placenta. the prevalence of toxoplasmosis in indian pregnant women is variably reported. however, the knowledge about this infection, its diagnosis and in ...200317642985
isolation of viable toxoplasma gondii from naturally infected aborted bovine fetuses.neospora caninum and toxoplasma gondii are related parasites. the former is a common cause of abortion in dairy cattle. the latter has not been conclusively demonstrated in bovine fetuses. during the course of attempts to isolate n. caninum from aborted fetuses, t. gondii was isolated from 2 aborted fetuses, 1 from portugal and 1 from the united states. both isolates were made by bioassay of fetal brains in mice. the fetus from portugal was about 5 mo in gestational age, and the fetus from the u ...200212537120
high prevalence of viable toxoplasma gondii infection in market weight pigs from a farm in massachusetts.the ingestion of uncooked infected meat is considered important in the epidemiology of toxoplasma gondii infection in humans and little is known of the prevalence of viable t. gondii in meat used for human consumption in the united states. in the present study, viable t. gondii was isolated from 51 out of 55 pigs destined for human consumption. hearts and tongues (500 g) from fifty-five 6-mo-old pigs from a farm in massachusetts were bioassayed for t. gondii by feeding them to t. gondii-free cat ...200212539744
[toxoplasmosis in poznan region, poland 1990-2000].the paper summarizes the results of the interdisciplinary studies on toxoplasmosis carried out in poznan region, poland. in the years 1990-2000 the specific toxoplasma gondii seropositivity rates in pregnant women decreased from 58.9% to 43.7%. significant was an increase in seropositivity in the age group 15-20 years. cats were seropositive in 70.6%; relatively high seropositivity rate was observed in cats kept at home only (65.7%). slaughtered pigs were positive in 13.2% with higher rates in o ...200212608090
serologic survey of toxoplasma gondii in noncarnivorous free-ranging neotropical mammals in french guiana.the aim of this study was to determine the frequency of toxoplasma infection in wild mammals, particularly noncarnivorous species, and to identify possible sources of infection for humans. a serological study was conducted that included 310 animals representing 10 species of terrestrial mammals from the same region (primary tropical rain forest inhabited by humans). toxoplasmosis was diagnosed using a direct agglutination test using formalin-treated toxoplasma gondii. the prevalence of antibodie ...200212656126
survival of nonsporulated toxoplasma gondii oocysts under refrigerator conditions.toxoplasma gondii oocysts are excreted nonsporulated in the feces of the cats into the environment. these oocysts must undergo sporulation to become infectious. little is known about the factors that influence sporulation of t. gondii oocysts. the present study examined the survival of nonsporulated oocysts under refrigerated conditions over 11-week observation period. microscopic examination of oocysts indicated that no visible development occurred under refrigerator conditions. the nonsporulat ...200211777609
biological and genetic characterisation of toxoplasma gondii isolates from chickens (gallus domesticus) from são paulo, brazil: unexpected findings.in spite of a wide host range and a world wide distribution, toxoplasma gondii has a low genetic diversity. most isolates of t. gondii can be grouped into two to three lineages. type i strains are considered highly virulent in outbred laboratory mice, and have been isolated predominantly from clinical cases of human toxoplasmosis whereas types ii and iii strains are considered avirulent for mice. in the present study, 17 of 25 of the t. gondii isolates obtained from asymptomatic chickens from ru ...200211796127
potential of beta-galactosidase-expressing toxoplasma gondii for in situ localization and observation of rare stages of the parasite life cycle.a cyst-forming strain of toxoplasma gondii was transfected with the escherichia coli lacz gene and expressed beta-galactosidase constitutively. this strain has been used to localize and analyze the early stages of development and reactivation of t. gondii in mice. the chromogenic detection of the enzyme allows an easy detection of the parasites after light fixation and therefore allows a submacroscopic analysis of tissue distribution within the organism. also, it allows further embedding and ret ...200211822740
cervical cat scratch disease lymphadenitis in a patient with immunoglobulin m antibodies to toxoplasma gondii.we report on a young patient with chronic cervical lymphadenopathy and serological and histological evidence for infection with bartonella henselae and toxoplasma gondii. serological follow-up studies, including testing for avidity of toxoplasma-specific immunoglobulin g antibodies, assisted in the determination of the cause of the acute lymphadenitis. our results suggest that the clinical symptoms were most likely due to cat scratch disease rather than to acute toxoplasmosis.200211874902
studies on serological cross-reaction of neospora caninum with toxoplasma gondii and hammondia heydorni.the enzyme-linked immunosorbent assay (elisa) was used to examine cross-reactivity of neospora caninum with toxoplasma gondii and hammondia heydorni. anti-t. gondii mouse and cat sera cross-reacted with n. caninum soluble antigen (nla), but not with the recombinant surface antigen (ncsrs2). anti-h. heydorni dog sera showed no cross-reactivity with either the nla antigen or the ncsrs2. lack of cross-reactivity between anti-h. heydorni sera and n. caninum antigens, and the cross-reactivity of anti ...200211913555
recombinant feline herpesvirus type 1 expressing toxoplasma gondi rop2 antigen inducible protective immunity in cats.in order to investigate whether a recombinant viral vaccine composed of a feline herpesvirus type 1 (fhvi) vector and an immunogenic antigen of toxoplasma gondii can induce a protective immunity in cats, a recombinant fhv1 expressing rop2 antigen of t. gondii was prepared. we introduced a dna fragment encoding 1-538 amino acid residues of rop2 precursor into fhv1 genome under the control of a cytomegalovirus promoter. the recombinant fhv1 (fhv/rop2) successfully expressed a 59 kda antigen that w ...200211936503
inoculation with bartonella henselae followed by feline herpesvirus 1 fails to activate ocular toxoplasmosis in chronically infected cats.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 a ...200212027509
non-lethal infection parameters in mice separate sheep type ii toxoplasma gondii isolates by virulence.the zoonotic protozoan parasite toxoplasma gondii can infect all warm-blooded animals, but virulence of isolates has previously been characterised mainly by the ability to kill mice after experimental infections. in the present study, 15 type ii strains of t. gondii, isolated from five adult sheep, six sheep abortions, two pigs, one cat and one fox were examined for their virulence to young mice by less dramatic parameters. clinical disease of inoculated mice, directly evidenced by reduced weigh ...200212053916
prevalence of toxoplasma gondii antibodies in sera of domestic cats from guarulhos and são paulo, brazil.antibodies to toxoplasma gondii were determined in serum samples of 502 domestic cats from brazil by the modified agglutination test (mat), using formalin-fixed whole tachyzoites and mercaptoethanol. antibodies (mat > or = 1:20) were found in 132 (26.3%) of 502 cats. with respect to origin, antibodies were found in 26.7% of 430 stray cats from são paulo, 10% of 40 stray cats from guarulhos, and 40.6% of 32 cats from a cat breeder in são paulo. antibody titers were: 1:20 in 10 cats, 1:25 in 40 ca ...200212054029
use of near-infrared raman spectroscopy to detect igg and igm antibodies against toxoplasma gondii in serum samples of domestic cats.near-infrared raman spectroscopy (nirs) is a particularly promising technique that is being used in recent years formany biomedical applications. optical spectroscopy has gained increasing prominence as a tool for quantitative analysis of biological samples, clinical diagnostic, concentration measurements of blood metabolites and therapeutic drugs, and analysis of the chemical composition of human tissues. toxoplasmosis is an important zoonosis in public health, and domestic cats are the most im ...200212146716
cross-sectional study of serum antibodies against sarcocystis neurona in cats tested for antibodies against toxoplasma gondii.to determine apparent seroprevalence of antibodies against sarcocystis neurona in a population of domestic cats previously tested for antibodies against toxoplasma gondii.200212184700
isolation of purified oocyst walls and sporocysts from toxoplasma gondii.toxoplasma gondii oocysts are environmentally resistant and can infect virtually all warm-blooded hosts, including humans and livestock. little is known about the biochemical basis for this resistance of oocysts, and mechanism for excystation of t. gondii sporozoites. the objective of the present study was to evaluate different methods (mechanical fragmentation, gradients, flow cytometry) to separate and purify t. gondii oocyst walls and sporocysts. oocyst walls were successfully separated and p ...200212188226
tachyzoite-induced life cycle of toxoplasma gondii in cats.the tachyzoite-induced cycle of toxoplasma gondii was studied in 46 cats. tachyzoites of the m-7741 or me-49 strain of t. gondii were administered orally to cats by pouring into the mouth or by stomach tube, or by intraintestinal inoculation. ten weaned cats that had been inoculated with tachyzoites directly in the intestine were killed 1, 3, 6, 9, 12, 15, 18, or 25 days later, and their tissues were studied histologically and bioassayed in mice. toxoplasma gondii was demonstrable in the blood o ...200212197119
examination of attachment and survival of toxoplasma gondii oocysts on raspberries and blueberries.the consumption of toxoplasma gondii oocysts on fresh produce may be a means of its transmission to humans. cats shed t. gondii oocysts, which contaminate produce directly or contaminate water sources for agricultural irrigation and pesticide and fertilizer applications. cyclospora cayetanensis is a related coccidial parasite, and outbreaks of diarrhea caused by c. cayetanensis have been associated with the ingestion of contaminated raspberries. the oocysts of these coccidians are similar in siz ...200212197133
prevalence of toxoplasma gondii antibodies in domestic cats from rural ohio.antibodies to toxoplasma gondii were determined in serum samples from 275 domestic cats from a mobile spay and neuter clinic from 8 counties in ohio. the modified agglutination test incorporating whole formalinized tachyzoites and mercaptoethanol was used to determine antibodies. antibodies to t. gondii were found in 133 (48%) out of 275 cats: in titers of 1:25 in 24, 1:50 in 37, and 1:500 or more in 72. the highest prevalence (62% of 78) was in outdoor cats. the prevalence of t. gondii antibodi ...200212197137
development and evaluation of an enzyme-linked immunosorbent assay with recombinant sag2 for diagnosis of toxoplasma gondii infection in cats.cats are pivotal in the transmission of toxoplasma gondii. to develop a sensitive and specific serodiagnostic method for feline toxoplasmosis, surface antigen 2 (sag2) of t. gondii was expressed in escherichia coli and its diagnostic potential evaluated in an enzyme-linked immunosorbent assay (elisa). the elisa with recombinant sag2 (rsag2) was able to differentiate very clearly between sera from cats experimentally infected with t. gondii and sera from normal cats. serum samples collected from ...200212197139
comparative analysis of antisense rna, double-stranded rna, and delta ribozyme-mediated gene regulation in toxoplasma gondii.rna tools, namely, antisense rna, double-stranded rna (dsrna), and delta ribozyme, were comparatively analyzed for the development of effective rna-based gene modulators. the gene encoding uracil phosphoribosyltransferase (uprt) of toxoplasma gondii was used as a target and a negative selectable marker. using plasmid transformation and drug selection assays, we obtained t. gondii transformants resistant to 5-fluoro-2'-deoxyuridine (fdur), the cytotoxic prodrug and substrate of uprt, when the pla ...200212238816
a computer simulation of the prevention of the transmission of toxoplasma gondii on swine farms using a feline t. gondii vaccine.transmission of toxoplasma gondii on swine farms was investigated using a deterministic dynamic computer simulation model. a primary focus was to evaluate a feline t. gondii vaccine. animal populations (swine and cats) were compartmentalized based on the stage of t. gondii infection. simulations were run under conditions of closed and equilibrium population size. model parameters were varied in a factorial experimental design to test the following hypotheses: t. gondii infection in finishing pig ...200212324204
evidence for nuclear localisation of two stage-specific isoenzymes of enolase in toxoplasma gondii correlates with active parasite replication.the protozoan parasite toxoplasma gondii has a complex life cycle involving the developmental transition between the asexual exo-enteric stages (tachyzoites and bradyzoites) and the coccidian (sexual and asexual) forms (schizonts, macrogametes and microgametes). previous work has established the stage-specific expression of certain proteins including two glycolytic isoenzymes of enolase and lactate dehydrogenase in t. gondii. here we describe the expression and subcellular localisation of the tw ...200212350375
toxoplasma gondii: transmission, diagnosis and prevention.toxoplasmosis, caused by the protozoan parasite toxoplasma gondii, is one of the most common parasitic infections of man and other warm-blooded animals. it has been found world-wide from alaska to australia. nearly one-third of humanity has been exposed to this parasite. in most adults it does not cause serious illness, but it can cause blindness and mental retardation in congenitally infected children and devastating disease in immunocompromised individuals.200212390281
toxoplasmosis in pallas' cats (otocolobus felis manul) at the denver zoological gardens.in may 1996 the denver zoological gardens obtained two male and two female pallas' cats (otocolobus felis manul) that were wild-caught in the ukraine. these animals were part of a group of 16 wild-caught adults (eight male and eight female) imported to the united states and canada between 1995 and 1996. the denver zoological gardens cats were quarantined at the zoo hospital for approximately i mo. during the quarantine period they were immobilized for physical examination, and sera were obtained ...200212398302
characterization of toxoplasma gondii sag2 expressed in insect cells by recombinant baculovirus and evaluation of its diagnostic potential in an enzyme-linked immunosorbent assay.a baculovirus carrying the sag2 gene of toxoplasma gondii was constructed, and recombinant sag2 protein (s-rsag2) was expressed in insect cells. s-rsag2 was recognized by sera from cats and pigs infected with t. gondii. mice immunized with s-rsag2 produced high titers of specific immunoglobulin g2a (igg2a) and igg1 antibodies. in an indirect fluorescent antibody test, all mouse antisera against s-rsag2 reacted strongly to the natural parasites, but those against rsag2 expressed in escherichia co ...200212414772
serological survey of toxoplasma gondii, feline immunodeficiency virus and feline leukaemia virus in urban stray cats in belgium.three hundred and forty-six serum samples taken between 1998 and 2000 from urban stray cats in the city of ghent were tested for antibodies to toxoplasma gondii and feline immunodeficiency virus (fiv), and antigens of feline leukemia virus (felv). of these 346 samples, 243 (70.2 per cent) were seropositive for tgondii. thirty-nine cats (11.3 per cent) had antibodies against fiv and 13 (3.8 per cent) had circulating antigens of felv. fewer of the female cats had fiv and heavier cats had a higher ...200212479298
epidemiologic investigation of seroprevalence of antibodies to toxoplasma gondii in cats and rodents.to provide an epidemiologic investigation of the seroprevalence of antibodies to toxoplasma gondii in populations of cats and wild rodents in rhode island and to address the possible epidemiologic role of wild rodents in the spread of toxoplasmosis.200212492287
toxoplasma gondii infection of cats in epizootiological and clinical aspects.a total of 200 cats from a south-western region of poland were tested for antibodies to t. gondii. 105 (52.5%) examined cats were seropositive for t. gondii. positive results were found in 16 (50%) out of 30 homeless cats, 33 (55%) out of 60 cats kept in shelters, and 56 (51.85%) out of 108 pet cats visiting outpatients clinics. 70 of pet cats stayed indoor and never left house, the others (38 cats) lived at house, but frequently abided outdoor. the seroprevalence in the last group was higher th ...200212512555
the influence of feeding and maintenance system on occurrence of toxoplasma gondii infections in dogs.serum samples of 113 dogs visiting "outpatient clinics", 52 dogs kept in shelters and 35 animals from a military dog training centre were examined for toxoplasma gondii specific antibodies using a latex agglutination test. significant differences in seroprevalences were found between dogs from the training centre (8.6% of positive results) and the other populations examined (40.7% of positive seroreagents in animals visiting outpatient clinics and 44.2% in the group from shelters, respectively). ...200212512556
congenital toxoplasmosis.toxoplasma gondii, a parasite, has three modes of transmission: oral intake of raw or undercooked meat or contaminated fruits and vegetables, ingestion of materials contaminated with cat feces, and transplacental infection. the focus of this article is congenital toxoplasmosis, which is transmitted to the fetus across the placenta. when primary infection of the mother occurs during pregnancy, there is a 40 percent chance of fetal infection; rate of transmission and severity of infection are rela ...200112143899
the schizophrenia-rheumatoid arthritis connection: infectious, immune, or both?schizophrenia and rheumatoid arthritis share an impressive number of similarities. both are chronic, relapsing diseases of unknown etiology. both became prominent in the early 19th century and have prevalences of approximately 1% in north america and europe. both run in families, have pairwise concordance rates of approximately 30% among monozygotic twins, and are more common among individuals born in urban areas. for both diseases, studies have reported greater exposure to cats in childhood tha ...200111782106
[seroepidemiology of toxoplasmosis in a marginal community of the municipality of maracaibo, zulia state, venezuela].the goal of this study was to determine the prevalence of anti-toxoplasma gondii antibodies in a marginal community of the municipality of maracaibo, zulia state, venezuela and if there was a relationship between risk factors and infection. an epidemiological survey of personal data, living sanitary conditions and contact with cats was performed. a collection of 254 blood samples from male and female individuals, with ages ranging from 8 months to 76 years, was studied. anti-toxoplasma gondii re ...200111416977
clinical ocular toxoplasmosis in neonatal kittens.to describe ocular findings in kittens with congenital or early neonatal infection by toxoplasma gondii and to determine if there are detectable differences in disease caused by three strains.200111422988
toxoplasma gondii antibodies in exotic wild felids from brazilian zoos.serum samples from 37 captive exotic felids in 12 zoos from six brazilian states were assayed for antibodies to toxoplasma gondii by the modified agglutination test using formalin-fixed whole tachyzoites. titers greater than or equal to 1:20 were considered positive. antibodies to t. gondii were found in 24 of 37 (64.9%) felids, including one european lynx (lynx lynx), two jungle cats (felis chaus), two servals (leptailurus serval), two tigers (panthera tigris), three leopards (panthera pardus), ...200112785684
a 14-3-3 protein homologue is expressed in feline enteroepithelial-stages of toxoplasma gondii.fourteen cdna clones encoding epitopes of proteins of toxoplasma gondii feline enteroepithelial-stages parasites were isolated and expressed in escherichia coli in an effort to determine the antigenecity of the parasites. sequence analysis showed that four of the cdna clones had a 930-bp open-reading frame encoding a product showing similarity to the 14-3-3 protein mrna sequence.(1) southern hybridization of dig-labeled positive clone with t. gondii genomic dna cleaved with ecori, bamhi and hind ...200111182236
oocyst shedding by cats fed isolated bradyzoites and comparison of infectivity of bradyzoites of the veg strain toxoplasma gondii to cats and mice.infectivity of bradyzoites of the veg strain of toxoplasma gondii was compared in cats and mice. for this, tissue cysts were separated from brains of infected mice using a percoll gradient, and bradyzoites were released by incubation in acidic pepsin solution. after filtration through a 3-microm filter, bradyzoites were counted and diluted 10-fold in rpmi tissue culture medium. dilutions estimated to have 1, 10, 100, and 1,000 bradyzoites were fed to cats and inoculated into mice, orally or subc ...200111227895
analysis of the humoral responses of toxoplasma gondii-infected cats using immunofluorescent assays with tachyzoite, bradyzoite, and gametogenic stages.we investigated levels of toxoplasma gondii specific antibodies present in sera, intestinal secretions, and fecal extracts obtained from cats following primary and challenge infections. antibodies specific to t. gondii tachyzoites, bradyzoites, sporozoites, and enteroepithelial stages were detected by indirect immunofluorescence assay. enteroepithelial stage-specific antibodies were detected in serum as early as 2 wk after infection, whereas antibodies from intestinal secretions did not appear u ...200111227907
toxoplasma gondii. 200111313530
antibody levels in goats fed toxoplasma gondii oocysts.outbred goats were fed 10(5) toxoplasma gondii oocysts and were monitored twice weekly for 8 wk for rectal temperature, clinical signs, parasitemia, and antibody levels by indirect fluorescence antibody test (ifat), latex agglutination test (lat), and indirect enzyme-linked immunosorbent assay (elisa). after 8 wk, all goats were killed, and samples of heart, skeletal muscle, brain, lymph nodes, kidneys, and liver were bioassayed in mice. anorexia, fever, and lethargy were observed from day 3 to ...200111318584
ocular and encephalic toxoplasmosis in canaries.in this report we describe the lesions produced by the protozoal organism, toxoplasma gondii, in the eyes and brain of the common yellow canary (serinus canaria). nine of 15 birds in a flock were affected with blindness, which developed over a 3-mo span, and two birds developed torticollis. microscopic alterations within the eye consisted of a nonsuppurative chorioretinitis with large numbers of macrophages that contained the tachyzoite form of t. gondii in the subretinal space, and aggregates o ...200111332494
congenital toxoplasmosis: a review.toxoplasmosis is caused by infection with the protozoan parasite toxoplasma gondii. in the united states, approximately 85% of women of childbearing age are susceptible to acute infection with t. gondii. acute infections in pregnant women may cause serious health problems when the organism is transmitted to the fetus (congenital toxoplasmosis), including mental retardation, seizures, blindness, and death. an estimated 400 to 4000 cases of congenital toxoplasmosis occur in the u.s. each year. man ...200111333376
diagnosis of naturally occurring toxoplasmosis by bronchoalveolar lavage in a cat.a 5-year-old cat presented with a history of fever and respiratory distress of 7 days' duration. the cat did not respond to initial symptomatic treatment. through use of a bronchoalveolar lavage (bal) technique, the diagnosis of toxoplasmosis was obtained rapidly without evidence of adverse effects to the cat. antemortem diagnosis of naturally occurring active toxoplasma gondii infection can be difficult in cats. identification of organisms obtained by bal may be beneficial in the diagnosis of f ...200111361117
toxoplasmosis.toxoplasma gondii is a unicellular protozoan. the definitive hosts, cats, produce hardy oocysts and sporozoites. ingestion by a nonfeline leads to the formation of tachyzoites acutely, which cause parasitemia and further dissemination, and bradyzoites, which lead to latent infection with the formation of tissue cysts in skeletal muscle, heart muscle, and central nervous system (cns) tissue. toxoplasmosis can be transmitted to humans by ingestion of tissue cysts in raw or inadequately cooked infe ...200111378431
dual sarcocystis neurona and toxoplasma gondii infection in a northern sea otter from washington state, usa.dual sarcocystis neurona and toxoplasma gondii infection was observed in a northern sea otter from washington, usa. the animal was found stranded, convulsed, and died shortly thereafter. encephalitis caused by both s. neurona and t. gondii was demonstrated in histological sections of brain. immunohistochemical examination of sections with s. neurona specific antisera demonstrated developmental stages that divided by endopolygeny and produced numerous merozoites. pcr of brain tissue from the sea ...200111390085
decrease of psychomotor performance in subjects with latent 'asymptomatic' toxoplasmosis.toxoplasma gondii is known to induce specific behavioural changes in its intermediate hosts. this is usually considered to be an evolutionary adaptation aimed to increase the probability of transmission of the parasite into its definitive host, the cat, by predation. in rodents an increase of reaction time as well as many other specific behavioural patterns have been observed. here we report the results of our double blind study showing the significantly longer reaction times of 60 subjects with ...200111393824
further remarks on hammondia hammondi and the taxonomic importance of obligate heteroxeny.in this opinion-paper reasons are given why hammondia hammondi cannot be considered as a separate species, but should be kept as a species of the genus toxoplasma, if not a strain of toxoplasma gondii.200111484857
seroepidemiology of toxoplasmosis in amerindians from western venezuela.a survey of 447 amerindians aged 1-69 years (mean age, 18.6 +/- 15.8 years) in 3 mountain and 1 lowland communities from venezuela were studied to determine the seroprevalence of toxoplasma gondii, the environmental risk factors for the infection, and how the process of acculturation may affect the transmission rate. serum samples were tested for immunoglobulin g antibodies by a commercial indirect hemagglutination test. the overall prevalence of infection was 49.7% (222 of 447) and ranged 38.2- ...200111508387
direct exposure to animal enteric pathogens.humans have very close interactions with working, food-producing, and companion animals. according to the american veterinary medical association, there are more than one hundred million cat and dog pets in the united states. furthermore, non-traditional pets like reptiles and exotic birds are not unusual companion animals in households. in addition to sharing with animals our living and/or working space and time, we also share, unfortunately, many disease causing microorganisms. in the past few ...200111512628
construction of recombinant feline herpesvirus type 1 expressing toxoplasma gondii surface antigen 1. 200111551636
rats, cats, people and parasites: the impact of latent toxoplasmosis on behaviour.the manipulation hypothesis states a parasite may alter host behaviour for its own benefit, often by enhancing its transmission rate through the food chain. this paper reviews studies on the potential impact of one parasite, toxoplasma gondii, on host behaviour, both on rodents, where altered responses may be proposed to benefit the parasite, and humans, where altered responses may arise as a side-effect of infection with no current adaptive significance.200111580990
toxoplasmosis. are cats really the source?toxoplasmosis is a zoonotic infection caused by the parasite toxoplasma gondii. it would appear to be one of the commonest human infections, but is usually asymptomatic. it is only problematic if the patient is pregnant or immunosuppressed.200111681144
toxoplasma gondii infection: relationship between seroprevalence and risk factors among inhabitants in two offshore islands from taiwan.a seroepidemiological study of toxoplasmosis among inhabitants of penghu island and kinmen island offshore of taiwan was performed using the latex agglutination test from july 1999 to june 2000. in order to determine risk factors for toxoplasma gondii (t. gondii) infection, the effects of a history of eating raw/undercooked meats and raising pets were focused on using a self-administrated questionnaire. the seroprevalence (28.2%; 190/673) in kinmen island was significantly higher than that (2.71 ...200111688954
detection of toxoplasma gondii in the milk of experimentally infected lactating cats.tachyzoites of toxoplasma gondii have been found in the milk of sheep, goats, cows and mice and infection by ingestion of raw goat milk has been documented in humans. lactational transmission from infected cats to their kittens is suspected but the organism has not been detected in the milk. the purpose of this study was to demonstrate the presence of t. gondii in the milk of experimentally infected cats. pregnant specific pathogen free cats were inoculated orally with t. gondii at various times ...200111705649
serodiagnosis of toxoplasma gondii infection in cats by enzyme-linked immunosorbent assay using recombinant sag1.the gene encoding surface antigen 1 (sag1, p30) of toxoplasma gondii (t. gondii) was cloned into the plasmid pgex-4t-3 and subsequently expressed in escherichia coli (e. coli) as a glutathione-s-transferase (gst) fusion protein. the recombinant sag1 (rsag1) was refolded using 8m urea solution followed by dialysis and thereafter evaluated in an enzyme-linked immunosorbent assay (elisa) for serological diagnosis of toxoplasmosis. the test sera were adsorbed with gst to block non-specific reactivit ...200111705650
high levels of congenital transmission of toxoplasma gondii in a commercial sheep flock.our current understanding of congenital transmission of toxoplasma gondii from ewe to lamb dictates that infection frequently results in abortion and the death of the developing foetus, that the birth of live infected lambs occurs rarely and that the cat is the predominant source of infection in ewes. using direct polymerase chain reaction detection of t. gondii, we report high levels of congenital transmission occurring in a commercially managed sheep flock. we sampled foetal-derived placental ...200111730799
serological study of toxoplasma gondii in kidney recipients.toxoplasma gondii igg antibodies were determined in 200 kidney recipients by the sabin-felmand dye test. twenty-two (11%) cases were positive for antibody detection. there was a statistically significant difference in the history of taking under-cooked meat, between the number of sero-positive cases and that of sero-negative subjects (63.6% vs 28.8%, p = 0.02). no such significant difference was evident regarding cat ownership (13.6% vs 22.0%, p = 0.3). sixteen (72.6%) of the 22 subjects with po ...200111758849
seroprevalence of toxoplasma gondii in captive neotropical felids from brazil.seroprevalence of toxoplasma gondii was determined in 865 captive neotropical felids from 20 states from brazil, sampled from september 1995 to april 1997. sera were tested by the modified agglutination test (mat) using formalin-fixed whole tachyzoites and mercaptoethanol. antibodies (mat> or =1:20) to t. gondii were found in 472 of 865 (54.6%) cats: in 45 of 99 (45.9%) jaguarundis (herpailurus yagouaroundi), in 97 of 168 (57.7%) ocelots (leopardus pardalis), in 68 of 131 (51.9%) oncillas (l. ti ...200111777601
[frequency of anti-toxoplasma gondii antibodies in cats from valdivia city, chile].toxoplasmosis is a parasitic zoonosis. the importance of the cat as related to this parasitosis lies in the fact that it is not only the definite host of the parasite, but responsible for its dissemination through the release of oocysts, which subsequently infect both humans and other animals. the objective of this study was to determine the serological prevalence of toxoplasma gondii in the feline population of the city of valdivia (chile) and to establish the possible epidemiological implicati ...200011338982
monoclonal antibodies to hammondia hammondi allowing immunological differentiation from toxoplasma gondii.five murine monoclonal antibodies (mabs) were developed against purified sporozoites of hammondia hammondi. despite a large antigenic similarity between the 2 closely related coccidia, h. hammondi and toxoplasma gondii, these mabs only reacted with h. hammondi. three mabs, id3, 3f2, and 4c9-7, recognized antigens of 38 kda localized in rhoptries (1d3), in rhoptries and in oocyst and cyst walls (3f2), and in rhoptries and the apical region (4c9-7). another mab, 4c9-10, reacted with a 27-kda antig ...200011191919
prevalence of enteric zoonotic organisms in cats.to determine prevalence of enteric zoonotic organisms in cats in north-central colorado.200010707683
[the occurrence of toxoplasma gondii and neospora caninum as regards meat hygiene].toxoplasma gondii and neospora caninum are phenotypically and phylogenetically closely related cyst-forming coccidia, both of which may cause abortion in livestock animals. t. gondii exhibits also zoonotic potential by causing diaplacental infections in the human fetus and harmful infections in immunosuppressed individuals. humans get infected either by consuming inappropriately prepared cyst-containing meat or by ingesting oocysts originating from cat feces. therefore, in order to assess infect ...200010748708
fatal toxoplasmosis in free-ranging endangered 'alala from hawaii.the 'alala (corvus hawaiiensis) is the most endangered corvid in the world, and intensive efforts are being made to reintroduce it to its former native range in hawaii. we diagnosed toxoplasma gondii infection in five free-ranging 'alala. one 'alala, recaptured from the wild because it was underweight and depressed, was treated with diclazuril (10 mg/kg) orally for 10 days. antibodies were measured before and after treatment by the modified agglutination test (mat) using whole t. gondii tachyzoi ...200010813600
biological and molecular characterizations of toxoplasma gondii strains obtained from southern sea otters (enhydra lutris nereis).toxoplasma gondii was isolated from brain or heart tissue from 15 southern sea otters (enhydra lutris nereis) in cell cultures. these strains were used to infect mice that developed antibodies to t. gondii as detected in the modified direct agglutination test and had t. gondii tissue cysts in their brains at necropsy. mouse brains containing tissue cysts from 4 of the strains were fed to 4 cats. two of the cats excreted t. gondii oocysts in their feces that were infectious for mice. molecular an ...200010864250
sources of toxoplasma infection in pregnant women: european multicentre case-control study. european research network on congenital toxoplasmosis.to determine the odds ratio and population attributable fraction associated with food and environmental risk factors for acute toxoplasmosis in pregnancy.200010894691
characterisation of toxoplasma gondii isolates using polymerase chain reaction (pcr) and restriction fragment length polymorphism (rflp) of the non-coding toxoplasma gondii (tgr)-gene sequences.the toxoplasma gondii (tgr) genes constitute a family of non-coding sequences, three of which have been previously described as possible tools for typing of toxoplasma gondii isolates. we obtained new isolates of t. gondii from domestic and wild animals, and used these to evaluate the possibility of using tgr gene variants as markers to distinguish among t. gondii isolates from different animals and different geographical sources. based on the band patterns obtained by restriction fragment lengt ...200010899531
seroprevalence of bartonella henselae and toxoplasma gondii among healthy individuals in thailand.the seroprevalence of bartonella henselae and toxoplasma gondii among apparently healthy individuals, mainly blood donors, in thailand was investigated by an indirect fluorescent antibody technique and by a latex agglutination test, respectively. of 163 serum samples examined, 9 (5.5%) were found to be positive for b. henselae-igg, 2 (1.2%) for b. henselae-igm, and 5 (3.1%) for the t. gondii antibody. no significant difference was observed between male and female samples in the serological test ...200010907691
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