首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 15 毫秒
1.
Six cows and 6 calves were each inoculated with 100 or 100,000 Toxoplasma gondii oocysts. Serum samples were analyzed, using the Sabin-Feldman dye test (DT), indirect hemagglutination test, latex agglutination test, and the modified direct agglutination test (MAT). Antibody titers in cows were lower than in calves. In the cows, DT titers increased briefly during the first month after inoculation, after which the titers were negative; however, T gondii was isolated from the tissues of 4 cows. Indirect hemagglutination and latex agglutination titers were generally less than 1:256. The MAT titers increased to 1:1,024 during the first month after inoculation. In 5 of the 6 cows, the MAT titers persisted. The 6th cow had a preinoculation MAT titer of 1:2,000 for 3 to 6 months. Therefore, the DT was not useful in serologic surveys for T gondii in cattle; the MAT was the most sensitive test and may be useful in the diagnosis of T gondii infection in cattle.  相似文献   

2.
Little is known of the prevalence of Toxoplasma gondii in commercially raised chickens. In the present study, the prevalence of T. gondii in 96 free-range chickens (Gallus domesticus) from a commercial farm in Israel 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 found in 45 of the 96 chickens. Hearts and brains of seropositive (MAT > or = 1:5) chickens were bioassayed in mice. Additionally, hearts and brains of 51 seronegative (MAT < 1:5) chickens were bioassayed in two T. gondii-free cats. T. gondii was isolated from 19 of the 45 (42.2%) seropositive chickens by bioassay in mice. Both the cats fed tissues pooled from seronegative chickens shed T. gondii oocysts. Tachyzoites and tissue cysts of all 21 isolates of T. gondii from chickens were avirulent for mice. Seventeen of the 19 isolates genotyped were found to be type II, and 2 were type III. Understanding of the sources of infection on such farms could be the key to the development of better prevention strategies.  相似文献   

3.
Cats are considered essential for the maintenance of Toxoplasma gondii in nature. However, T. gondii infection has been reported in arctic fox (Vulpes lagopus) from the Svalbard high arctic archipelago where felids are virtually absent. To identify the potential source of T. gondii, we attempted to isolate and genetically characterize the parasite from arctic foxes in Svalbard. Eleven foxes were trapped live in Grumant (78 degrees 11'N, 15 degrees 09'E), Svalbard, in September 2005 and 2006. One of the foxes was found to be seropositive to T. gondii by the modified agglutination test (MAT). The fox was euthanized and its heart and brain were bioassayed in mice for the isolation of T. gondii. All 10 mice inoculated with brain tissue and one of the five inoculated with heart developed MAT antibodies, and tissue cysts were found in the brains of seropositive mice. Two cats fed tissues from infected mice shed T. gondii oocysts. Genotyping using 10 PCR-RFLP markers and DNA sequencing of gene loci BSR4, GRA6, UPRT1 and UPRT2 determined the isolate to be Type II strain, the predominant T. gondii lineage in the world.  相似文献   

4.
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   

5.
The seroprevalence of Toxoplasma gondii, Dirofilaria immitis (heartworm), feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) infections was examined using serum or plasma samples from 746 pet cats collected between May and July 2009 from clinics and hospitals located in and around Bangkok, Thailand. The samples were tested for heartworm, FIV, and FeLV using a commercial ELISA. Of the 746 samples, 4.6% (34/746) were positive for heartworm antigen, 24.5% (183/746) had circulating FeLV antigen, and 20.1% (150/746) had antibodies against FIV. In addition, the first 348 submitted samples were tested for T. gondii antibodies using a modified agglutination test (MAT, cut off 1:25); 10.1% (35/348) were seropositive. Of the 348 cats sampled for all four pathogens, 11, 10, and 1 were positive for T. gondii antibodies and FIV antibodies, FeLV antigen, or D. immitis antigen, respectively. Of the 35 T. gondii-seropositive cats, 42.9% (15/35) were co-infected with at least one of the other three pathogens. The presence of antibodies to FIV was significantly associated with both age and gender, while FeLV antigen presence was only associated with age. In the case of FIV, males were twice as likely to be infected as females, and cats over 10 years of age were 13.5 times more likely to be infected than cats less than 1 year of age. FeLV antigen was more common in younger cats, with cats over 10 years of age being 10 times less likely to be FeLV positive than cats under 1 year of age. This is the first survey for these four pathogens affecting feline health in Thailand.  相似文献   

6.
Thirty 5-month-old red-legged partridges (Alectoris rufa) reared in battery were divided into five groups: 4 birds in group A, 14 birds in group B, 4 birds in group C, 4 birds in group D and 4 birds in group E, and were inoculated orally with 10, 50, 10(2), 10(3) and 10(4) oocysts of the OV-51/95 strain of Toxoplasma gondii, respectively. During the experiment, blood samples from all birds were drawn every 3-7 days and at necropsy. Serologic response was measured by the modified agglutination test (MAT) and the latex agglutination test (LAT). One bird from each group was killed at 44, 58, 65 and 72 days after inoculation (DAI). From 72 DAI to the end of the experiment, surviving partridges from group B were killed at weekly intervals. The last partridges were sacrified 100 DAI. MAT was the most sensitive and specific test for detecting T. gondii antibodies in the birds. First positive titers were detected by MAT in all sera on 7 DAI, but titers by LAT did not appear until 13 DAI. Antibody titers detected by MAT on 7 DAI were higher in the partridges with the largest inocula (10(3) or 10(4) oocysts) than those inoculated with 10, 50 or 10(2) oocysts. All surviving birds developed a serologic response to T. gondii, with maximum titers of 512-32,768 in the MAT on 13-17 DAI, and positive titers persisted at least until 100 DAI. To the contrary, LAT reveals only very low antibody titers even in partridges inoculated with the highest dose of T. gondii.  相似文献   

7.
The prevalence of Toxoplasma gondii in free-ranging chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in free-range chickens (Gallus domesticus) from 11 Bio-farms in Austria was determined. Antibodies to T. gondii assayed by the modified agglutination test (MAT) were found in 302 of 830 (36.3%) chickens with titers of 1:10 in 50, 1:20 in 69, 1:40 in 53, 1:80 in 40, 1:160 or higher in 90. Hearts of 218 chickens with MAT titers of 10 or higher were bioassayed individually in mice. Tissues from 1183 chickens were pooled and fed to 15, T. gondii-free cats. Feces of the cats were examined for oocysts; 11 cats shed T. gondii oocysts. T. gondii was isolated from 56 chickens by bioassay in mice. Thus, there were 67 isolates of T. gondii from these chickens. Genotyping of these 67 isolates using the SAG2 locus indicated that all 33 were Type II. Phenotypically and genetically these isolates were different from T. gondii isolates from Brazil. None of the isolates was virulent for mice. This is the first report of isolation of T. gondii from chickens from Austria.  相似文献   

8.
Stray cat colonies in urban and rural areas of Lombardy, northern Italy, were surveyed for seroprevalence of feline immunodeficiency virus (FIV) antibodies, feline leukaemia virus (FeLV) antigen and Toxoplasma gondii IgG. Of 316 cats tested, 6.6% were positive for FIV and 3.8% were positive for FeLV infection; 203 cats were tested for T gondii IgG antibodies and a prevalence of 30.5% was detected. Statistical analysis tested the influence of provenience, age, gender, health status and laboratory results on seroprevalence and found male gender and adult age were risk factors for FIV infection. FIV-infected cats were more likely to have a decreased red blood cell count than FIV seronegative cats. No predictors were significantly associated with FeLV and T gondii seropositivity. Colony cats in this study posed a limited risk for retrovirus infection to pet cats allowed outdoors, whereas toxoplasmosis exposure was comparable with the worldwide data.  相似文献   

9.
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. Additionally, hearts and/or brains of most of the seronegative (MAT < 1:5) chickens were fed to 20 T. gondii-free cats, while 32 seropositive chickens (MAT 1:5) were fed to 3 cats. T. gondii was not isolated from any of the chickens by mouse bioassay. Five of the cats that were fed seronegative chickens shed oocysts, while isolates were not obtained from any of the other cats fed seropositive chickens. These five isolates, along with the two that were previously isolated in India through cat bioassay, were genetically analyzed. Genotyping using the SAG 2 locus indicated that two isolates were type II and five were type III. Microsatellite analysis revealed allelic differences between and within the lineages. This is the first report of genetic characterization of any T. gondii isolate from India.  相似文献   

10.
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 (MAT), were found in 49 (40.4%) chickens in titers of 1:5 in 11, 1:10 in four, 1:20 in four, 1:40 in eight, 1:80 in 10, and 1:160 or more in 12 chickens. Antibodies were found in three ducks each with a titer of 1:80. Hearts and brains of seropositive (MAT > or = 1:5) chickens and ducks were bioassayed in mice. Additionally, hearts and brains of seronegative (MAT<1:5) animals were bioassayed in T. gondii-free cats. T. gondii was isolated from 19 of 49 seropositive chickens (one with a titer of 1:5, two with a titer of 1:20, one with a titer of 1:40, five with a titer of 1:80, three with a titer of 1:160, and seven with a titer of > or = 1:360). One cat fed tissues pooled from 15 seronegative chickens shed T. gondii oocysts, while two cats fed tissues of 34 seronegative chickens did not shed oocysts. T. gondii was isolated from one of the seropositive ducks by bioassay in mice. The two cats fed tissues from 16 seronegative ducks did not shed oocysts. Genotyping of 20 chicken isolates of T. gondii using the SAG 2 locus indicated that 17 isolates were type III and three were type II. The duck isolate of T. gondii was type III. The mice inoculated with tissue stages of all 21 isolates of T. gondii from chickens and ducks remained asymptomatic, indicating that phenotypically they were not type I because type I strains are lethal for mice. Infections with mixed genotypes were not found.  相似文献   

11.
The prevalence of Toxoplasma gondii in free-ranging chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 144 free-range chickens (Gallus domesticus) from Costa Rica was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT), and found in 60 (40.1%) of 144 chickens with titers of 1:5 in 16, 1:10 in 5, 1:20 in 2, 1:40 in 3, 1:80 in 5, and 1:160 or higher in 29. Tissues of all chickens were bioassayed for T. gondii in mice or cats. Hearts and brains of 52 chickens with titers of 1:5 or higher and 16 chickens with doubtful titers were pooled and bioassayed in mice. Tissues from 76 chickens with MAT titers of 1:10 or less were pooled and fed to three T. gondii-free cats. Fecal floats of cats were bioassayed orally in mice but were negative for T. gondii oocysts. T. gondii was isolated by bioassay in mice from 32 chickens with MAT titers of 1:10 or higher. All infected mice from 4 of the 32 isolates died of toxoplasmosis. Genotyping of these 32 isolates using polymorphisms at the loci SAG1, SAG2, SAG3, BTUB and GRA6 revealed five genotypes. Five isolates had type I alleles and one isolate had type III alleles at all loci. The rest 26 isolates contained the combination of type I and II or I and III alleles and were divided into three genotypes. None was found to have genotype II alleles at all five loci. This is the first report of genetic characterization of T. gondii isolates from Costa Rica, Central America.  相似文献   

12.
Subclinical Toxoplasma gondii infection was induced in young and adult cats by oral administration of tissue cysts. An antibody-capture ELISA to detect anti-Toxoplasma IgM-class antibodies in the serum of cats was developed. The serologic response to experimental infection was followed in the 2 groups of cats by use of anti-Toxoplasma IgM and IgG detection. This study shows that anti-Toxoplasma IgM-class antibody titers develop early in the course of experimental infection in cats and that the combination of IgM- and IgG-class antibody titer measurement can aid in the detection of recent subclinical toxoplasmosis.  相似文献   

13.
The prevalence of Toxoplasma gondii in free-ranging chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 98 free-range chickens (Gallus domesticus) from Nicragua was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT), and found in 84 (85.7%) of 98 chickens with titers of 1:5 in 10, 1:10 in eight, 1:20 in seven, 1:40 in nine, 1:80 in 11, 1:160 in one, 1:200 in 27, 1:400 in six, 1:800 four, and 1:3200 in one bird. Hearts and brains of 32 chickens with titers of 1:10 or less were pooled and fed to three T. gondii-free cats. Hearts and brains of 66 chickens with titers of 1:20 or higher were bioassayed in mice. Feces of cats were examined for oocysts. The cat fed tissues from eight chickens with titers of 1:10 shed T. gondii oocysts. The two cats fed tissues of 24 chickens with titers of 1:5 or less did not shed oocysts. T. gondii was isolated by bioassay in mice from 47 chickens with MAT titers of 1:20 or higher. All infected mice from six isolates died of toxoplasmosis. Overall, 41 of 170 (24.1%) mice that became infected after inoculation with chicken tissues died of toxoplasmosis. Genotyping of these 48 isolates (47 from mice and 1 from pooled tissues) using polymorphisms at the loci SAG1, SAG2, SAG3, BTUB and GRA6 revealed eight genotypes. Six isolates had Type I alleles, three isolate had Type II alleles and six isolates had Type III alleles at all loci. Four isolates had mixed infections. Two isolates have a unique allele at SAG1 locus and combination of I and III alleles at other loci. The rest 27 isolates contained the combination of Type I and III alleles and were divided into four genotypes. More than one genotypes were often isolated in chickens from the same household, indicating multiple genotypes were circulating in the same environment. This may explain the high frequency of mixed infections observed. High rate of mixed infection in intermediate hosts such as chickens may facilitate genetic exchange between different parasite lineages in definitive feline hosts. This is the first report of genetic characterization of T. gondii isolates from Nicragua, Central America.  相似文献   

14.
Serologic evidence of infection by Toxoplasma gondii, feline leukemia virus, feline coronaviruses, or feline immunodeficiency virus (FIV) is commonly found in cats with uveitis. Serum samples from 124 cats with uveitis were assayed by use of ELISA for the detection of T gondii-specific immunoglobulin M (IgM), IgG, and circulating antigens (Ag), as well as an ELISA for feline leukemia virus Ag, an ELISA for antibodies to FIV, and an indirect fluorescent antibody assay for antibodies to feline coronaviruses. Serologic evidence of infection by 1 or more of the infectious agents was detected in 83.1% of the samples. Serologic evidence of T gondii infection, defined as the detection of T gondii-specific IgM, IgG, or Ag in serum, was found in 74.2% of the samples. The seroprevalence of T gondii infection was significantly greater in cats with uveitis than in healthy cats from a similar geographic area. Serum samples from cats with serologic evidence of both T gondii and FIV infections were more likely to contain T gondii-specific IgM without IgG than samples from cats with serologic evidence of T gondii infection alone. Cats with serologic evidence of FIV and T gondii coinfection had a higher T gondii-specific IgM titer geometric mean and a lower T gondii-specific IgG titer geometric mean than did cats with serologic evidence of T gondii infection alone. Serologic evaluation for T gondii infection should include assays that detect IgM, IgG, and Ag, particularly in cats coinfected with FIV.  相似文献   

15.
The prevalence of Toxoplasma gondii in free-ranging chickens is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. The prevalence of T. gondii in 77 free-range chickens (Gallus domesticus) from Colombia, South America was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT), and found in 32 (44.4%) of 72 chickens with titers of 1:5 in 4, 1:10 in 3, 1:20 in 1, 1:40 in 1, 1:80 in 8, 1:160 in 8, 1:320 in 3, and 1:640 or higher in 4. Hearts and brains of 31 seropositive chickens were pooled and bioassayed in mice. Tissues from 32 (16+16) seronegative chickens were pooled and fed to two, T. gondii-free cats, and tissues from nine chickens without matching sera were fed to one T. gondii-free cat. Feces of cats were examined for oocysts. T. gondii oocysts were excreted by a cat that was fed tissues of 16 seronegative chickens. T. gondii was isolated by bioassay in mice from 23 chickens with MAT titers of 1:20 or higher. All infected mice from 16 of the 23 isolates died of toxoplasmosis. Overall, 82 (81.1%) of 101 mice that became infected after inoculation with chicken tissues died of toxoplasmosis. Genotyping of these 24 isolates using polymorphisms at the SAG2 locus indicated that seven T. gondii isolates were Type I, 17 were Type III, and none was Type II. Phenotypically, T. gondii isolates from chickens from Colombia were similar to isolates from Brazil but different from the isolates from North America; most isolates from chickens from Brazil and Colombia were lethal for mice whereas isolates from North America did not kill inoculated mice. Genetically, none of the T. gondii isolates from Colombia and Brazil was SAG2 Type II, whereas most isolates from chickens from North America were Type II. This is the first report of genetic characterization of T. gondii isolates from Colombia, South America.  相似文献   

16.
Eight pregnant goats were inoculated orally with 10 to 1,000 oocysts of Toxoplasma gondii at 83 to 102 days of gestation. Serum samples from the goats and from the kids born to them were analyzed, using the Sabin-Feldman dye test (DT), a commercially available modified agglutination test (MAT), and a latex agglutination test. Six of the does were observed for greater than 1 year; during this time, they delivered twice. All does developed DT and MAT antibody titers of greater than or equal to 1:2,048 within 29 days after inoculation, and the high titers persisted through the 2nd pregnancy; therefore, serologic results alone should not be relied on for the diagnosis of T gondii-induced abortion in does. On the other hand, all transplacentally infected kids had DT or MAT antibody titers of 1:2,048 before ingesting colostrum, indicating the usefulness of serologic evaluation of the fetus or stillborn kid in the diagnosis of abortion. Antibody was not found in the sera of noninfected kids born to Toxoplasma-infected does. The passively acquired colostral antibody declined by 5 months. Therefore, specific antibody found in adult goats is probably actively acquired. The commercially available MAT was simple, sensitive, and reliable for the diagnosis of caprine toxoplasmosis. The latex agglutination test needs further improvement, as titers rarely exceeded 1:256.  相似文献   

17.
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 seroprevalence of FIV. Exact logistic regression showed that cats that were infected with FIV were more likely to be infected with T gondii (P = 0.04), and the cats with FIV had a higher titre of Tgondii antibodies than FIV-negative animals. However, FeLV was not associated with either T gondii or FIV.  相似文献   

18.
An epizootic of toxoplasmosis among captive black-faced kangaroos (Macropus fuliginosus melanops) is reported. Eight of 25 adult kangaroos had antibodies to Toxoplasma gondii. Serologic data indicated recent exposure to T. gondii in six kangaroos. Two kangaroos had high T. gondii antibody titers (greater than or equal to 16,384) in the modified agglutination test and their infants died when less than 7 months old. Toxoplasma gondii tachyzoites were found in several organs of one infant kangaroo (joey) that died at about 82 days of age and numerous cysts were seen in skeletal muscles of the other joey that died at about 7 months of age. Adult kangaroos had subclinical infections. The modified agglutination test and the dye test were more sensitive than the indirect hemagglutination and latex agglutination tests for the detection of T. gondii antibodies in kangaroo sera.  相似文献   

19.
Neosporosis and toxoplasmosis are two important infections in young and adult sheep, leading to low production and abortion. This study aimed to determine the frequency of antibodies to Toxoplasma gondii and Neospora caninum in sheep from the eastern region of S?o Paulo State, Brazil. Serum samples (382) were collected from the sheep and assayed for T. gondii through modified agglutination test (MAT) and indirect fluorescent antibody test (IFAT), and for N. caninum antibodies, through IFAT, with cut-off titers equal to 16 (T. gondii) and 25 (N. caninum). All frozen samples were sent to the Center for Zoonoses Research (NUPEZO), Department of Veterinary Hygiene and Public Health (DHSVP), FMVZ, UNESP, for serological tests. A total of 71/382 (18.6%) samples reacted to T. gondii, especially at titers 16 (28; 39.4%), 64 (15; 21.1%), 256 (21; 29.6%) and 1024 (6; 8.5%) by MAT, and 16 (34; 47.9%), 64 (18; 25.4%), 256 (14; 19.7%) and 1024 (5; 7%) by IFAT. As regards N. caninum, 49/382 (12.8%) samples reacted at titers 25 (17; 34.7%), 50 (11; 22.5%), 100 (11; 22.5%), and ≥ 200 (10; 20.4%). These animals presented infection but no clinical signs. Six and ten animals had high titers for toxoplasmosis and neosporosis. No significant association was observed between antibodies for both parasites (P=0.535) according to Fisher's exact test, and no correlation was found between T. gondii (MAT) and N. caninum antibody titers (r=-0.0068; P=0.895), T. gondii (IFAT) and N. caninum antibody titers (r=-0.0025; P=0.961). Thus, T. gondii and N. caninum infections were observed in farms located in S?o Paulo State, where sheep play an important economical role for the national and regional business.  相似文献   

20.
The prevalence of Toxoplasma gondii in 84 free-range chickens (34 from the northern Pará state, and 50 from Rio Grande do Sul, the southern state) from Brazil, South America was determined. Antibodies to T. gondii were assayed by the modified agglutination test (MAT), and found in 39 (46.4%) of 84 chickens with titers of 1:10 in one, 1:20 in two, 1:40 in four, 1:80 in seven, 1:160 in five, 1:320 in six, 1:640 in eight and > or =1:1280 in six. Hearts and brains of 45 chickens with titers of 1:20 or less were pooled and fed to two T. gondii-free cats. Hearts and brains of 39 chickens with titers of 1:10 or higher were bioassayed in mice. Feces of cats were examined for oocysts. One cat fed tissues from 31 chickens with titers of less than 1:10 from Rio Grande do Sul shed T. gondii oocysts. T. gondii was isolated by bioassay in mice from 33 chickens with MAT titers of 1:20 or higher. All infected mice from 10 isolates died of toxoplasmosis. All 34 isolates (15 from Pará, 19 from Rio Grande do Sul) were genotyped using 11 genetic markers including SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, a new SAG2 and Apico. Eleven genotypes were revealed for Pará isolates and seven genotypes for Rio Grande do Sul. No genotype was shared between the two geographical locations. These data suggest that T. gondii isolates are highly diverse and genetically distinct between the two different regions in Brazil that are 3500 km apart.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号