Gondii B1 Gene Research Articles

Seroprevalence and genetic characterization of Toxoplasma gondii in masked palm civet (Paguma larvata) in Hainan province, tropical China

In the present study, the seroprevalence, risk factors and genotyping of Toxoplasma gondii in masked palm civet were investigated in tropical China. A total of 500 serum were collected from five administrative farms in tropical China, and assayed for T. gondii antibodies by modified agglutination test (MAT). The brain samples of 20 aborted fetuses were examined by semi-nested-PCR, and positive aborted fetuses (50%) were necropsied to collect the brain tissue for molecular and bioassay examinations. Genomic DNA was extracted from the 29 brain tissues of infected mice and T. gondii B1 gene was amplified using multilocus PCR-RFLP. Overall, 27.6% (95% CI: 23.682–31.518) of the animals was positive for T. gondii antibodies. Ages of masked palm civet was considered as a main risk factor associated with T. gondii infection. 4 DNA samples (13.8%) were positive for the T. gondii B1 gene. Three samples belong to ToxoDB#9, and one belongs to genotype the type II variant (ToxoDB genotype#3). Our results indicated that ToxoDB Genotype#9 has a distribution in masked palm civet that could be potential reservoirs for T. gondii transmission, which may pose a threat to human health.

Comparison of genotypes of Toxoplasma gondii in domestic cats from Australia with latent infection or clinical toxoplasmosis

Whether Toxoplasma gondii genotype is associated with disease severity in naturally occurring toxoplasmosis in domestic cats is unknown. The aim of this study was to compare genotypes of T. gondii in latently infected cats with those in cats with clinical toxoplasmosis. Results of a PCR targeting the B1 gene to detect T. gondii DNA were positive in tissue samples from 11 of 17 (65%) seropositive cats tested including four with clinical toxoplasmosis and seven with latent infections, as determined by serology, histologic findings and immunohistochemistry. Three of the four cats with clinical toxoplasmosis were immunosuppressed. Complete genotyping was performed in seven cats using PCR-RFLP at 12 loci (SAG1, 5′SAG2 and 3′SAG2, altSAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico) and direct sequencing of the multi-copy B1 gene. Partial genotyping using six loci was performed in one cat with latent infection. T. gondii type II (ToxoDB genotype #3) was determined in four cats with clinical toxoplasmosis and three cats with latent toxoplasmosis Novel T. gondii B1 gene polymorphisms were detected in two strains (at nucleotide posititions 233, 366 and 595) and a B1 gene polymorphism unique to Australia was identified in another (guanine/adenine at nucleotide position 378). One cat was co-infected with two or more type-II like strains at 3′SAG2. The results of this study suggest that the infecting T. gondii genotype, based on these 12 loci, is not a determinant of clinical disease in cats naturally infected with T. gondii and type II strains are prevalent in Australia.

Molecular detection and genetic characterization of Toxoplasma gondii infection in sika deer (Cervus nippon) in China

The objective of the present study was to investigate the prevalence and genetic characterization of Toxoplasma gondii infection in sika deer in China. During August 2014 to November 2014, a total of 450 tissue samples coming from 150 sika deer were collected to detect the T. gondii B1 gene using a nested PCR, and the positive samples were genotyped at 11 genetic markers (SAG1, 5′- and 3′-SAG2, alternative SAG2, SAG3, BTUB, GRA6, L358, PK1, c22-8, c29-2, and Apico) using multilocus polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology. Seventeen of 150 sika deer (11.33%) were tested positive by nested PCR. Six DNA samples from the 17 positive samples were completely typed, in which 4 samples from lung tissues, and 2 from muscular tissues, were identified as ToxoDB Genotype #9 (http://toxodb.org/toxo/). The results of the present study revealed the existence of T. gondii infection in sika deer in China, which provided the information of T. gondii genetic diversity in this host species. This study also indicated that ToxoDB Genotype #9 has a wide distribution in sika deer that could be potential reservoirs for T. gondii transmission, which may pose a threat to human health.

A Brazilian report using serological and molecular diagnosis to monitoring acute ocular toxoplasmosis.

BackgroundToxoplasmosis was recently included as a neglected disease by the Center for Disease Control. Ocular toxoplasmosis is one clinical presentation of congenital or acquired infection. The laboratory diagnosis is being used worldwide to support the clinical diagnosis and imaging. The aim of this study was to evaluate the use of serology and molecular methods to monitor acute OT in immunocompetent patients during treatment.MethodsFive immunocompetent patients were clinically diagnosed with acute OT. The clinical evaluation was performed by ophthalmologic examination using the Early Treatment Diabetic Retinopathy Study, best-corrected visual acuity, slit lamp biomicroscopy, fundoscopic examination with indirect binocular ophthalmoscopy color fundus photography, fluorescein angiography and spectral optical coherence tomography (OCT). Serology were performed by ELISA (IgA, IgM, IgG) and confirmed by ELFA (IgG, IgM). Molecular diagnoses were performed in peripheral blood by cPCR using the Toxoplasma gondiiB1 gene as the marker. Follow-up exams were performed on day +15 and day +45.ResultsOnly five non-immunocompromised male patients completed the follow up and their data were used for analysis. The mean age was 41.2 ± 11.3 years (median: 35; range 31–54 years). All of them were positive for IgG antibodies but with different profiles for IgM and IgA, as well as PCR. For all patients the OCT exam showed active lesions with the inner retinal layers being abnormally hyper-reflective with full-thickness disorganization of the retinal reflective layers, which assumed a blurred reflective appearance and the retina was thickened.ConclusionsThe presence of IgA and IgM confirmed the acute infection and thus was in agreement with the clinical evaluation. Our results show the adopted treatment modified the serological profile of IgM antibodies and the PCR results, but not the IgG and IgA antibodies and that imaging is a good tool to follow-up patients.Electronic supplementary materialThe online version of this article (doi:10.1186/s13104-015-1650-6) contains supplementary material, which is available to authorized users.

Toxoplasma gondii, Dirofilaria immitis, feline immunodeficiency virus (FIV), and feline leukemia virus (FeLV) infections in stray and pet cats (Felis catus) in northwest China: co-infections and risk factors.

This study was conducted to estimate the prevalence of Toxoplasma gondii, Dirofilaria immitis, feline immunodeficiency virus (FIV), and feline leukemia virus (FeLV) infections among stray and pet cats in Lanzhou, northwest China, and to identify the influence of age, gender, and regions on seropositivity. T. gondii antibodies were examined in cat sera by the modified agglutination test (MAT). The circulating antigens of D. immitis and FeLV and specific antibodies to FIV were examined using kits commercially available. The overall prevalence of T. gondii, FIV, FeLV, and D. immitis was 19.34, 9.12, 11.33, and 3.04 %, respectively. For the genetic characterization of T. gondii genotypes in cats, genomic DNA was extracted from the seropositive cats and the T. gondii B1 gene was amplified using a semi-nested PCR. DNA samples giving positive B1 amplification were then genotyped using multilocus PCR-RFLP. Two T. gondii genotypes (ToxoDB#9 and ToxoDB#1) were identified. Results of the multivariate logistic regression analysis showed that older cats are more likely to be seropositive than juveniles for T. gondii, FIV, FeLV, and D. immitis. This is the first report of T. gondii genotypes in cats in northwest China. Moreover, the present study is the first study of retrovirus and D. immitis seroprevalence in cats in China. The results revealed that T. gondii, FIV, and FeLV infections are common in stray and pet cats in northwest China.

Seroprevalence, risk factors and genetic characterization of Toxoplasma gondii in free-range white yaks (Bos grunniens) in China

The objective of this study was to determine the seroprevalence, risk factors and genotypes of Toxoplasma gondii in white yaks (Bos grunniens) in China. A total of 974 serum samples were collected from white yaks in Tianzhu Tibetan Autonomous County (TTAC), Gansu province, northwest China for detecting T. gondii antibodies by the modified agglutination test (MAT), and 414 tissues belonging to 138 white yaks were collected for detecting T. gondii DNA by amplification of B1 gene with a semi-nested PCR. A total of 155 serum samples (15.91%) were seropositive for T. gondii antibodies at a 1:100 cut-off, and 10 DNA samples (7.25%) were positive for the T. gondii B1 gene, which were genetically characterized using multilocus PCR-RFLP. Only one genotype (ToxoDB#9) was identified from two samples with complete genotyping results. Statistically significant differences were not observed between T. gondii seroprevalence and gender, season or pregnancy in the logistic regression analysis (P>0.05). Ages of white yaks was considered as a main risk factor associated with T. gondii infection. Our results indicated a widespread exposure to T. gondii among white yaks, and revealed the genotype ToxoDB#9 of T. gondii in white yaks for the first time in China.

Toxoplasma gondii infection in cancer patients: Prevalence, risk factors, genotypes and association with clinical diagnosis

Prevalence of human infection with Toxoplasma gondii has been increasing in China due to the increasing number of cats. However, little is known of the epidemiology of T. gondii infection in different cancer patient groups. Thus, a case–control study of 900 cancer patients and 900 controls was conducted to detect anti-T. gondii antibodies by ELISA in China. Genomic DNA was extracted from the diseased tissues of 510 patients and the T. gondii B1 gene was amplified using a semi-nested PCR. DNA samples giving positive B1 amplification were then genetically characterized using multi-locus PCR-RFLP. The prevalence of anti-T. gondii IgG in cancer patients (35.56%) was significantly higher than that in controls (17.44%). The highest T. gondii seroprevalence was detected in lung cancer patients (60.94%), followed by cervical cancer patients (50%), brain cancer patients (42.31%) and endometrial cancer patients (41.67%). Exposure with soil and consumption of raw/undercooked meat were significantly associated with T. gondii infection in cancer patients. Three T. gondii genotypes (ToxoDB#9, ToxoDB#10 and Type I variant) were identified. In conclusion, T. gondii infection is a severe problem in cancer patients and it is imperative that improved integrated measures should be conducted to prevent and control T. gondii infection in cancer patients.

Seroprevalence, risk factors and genotyping of Toxoplasma gondii in domestic geese (Anser domestica) in tropical China.

BackgroundLittle information is available about the seroprevalence of Toxoplasma gondii infection in geese (Anser domestica) in China. In the present investigation, the seroprevalence, risk factors and genotyping of T. gondii in geese were investigated in Hainan province, tropical China.FindingsA total of 600 serum samples and 150 brain tissue samples were collected from six administrative regions in tropical China, and assayed for T. gondii antibodies by Indirect Haemagglutination (IHA) test. Genomic DNA was extracted from the 30 brain tissues of seropositive geese and T. gondii B1 gene was amplified using a semi-nested PCR. DNA samples giving positive B1 amplification were then genetically characterized using multi-locus PCR-RFLP. Overall, 17% (95% CI: 14–20) of the animals were positive for T. gondii antibodies. Presence of cats in the household (odds ratio, OR 3), hygiene (OR 2.3) and presence of stray cat around the house (OR 2.3) were considered as main risk factors associated with T. gondii infection. Of 30 DNA samples, three were positive for the T. gondii B1 gene, two showed complete genotyping results. Only one genotype (type II) was identified.ConclusionsThe results of the present survey indicated the presence of T. gondii infection in geese in tropical China. Therefore, it is imperative that improved integrated measures be carried out to prevent and control T. gondii infection in geese in this province. This is the first report documenting the occurrence of T. gondii genotype in geese in China.

Genotyping of Toxoplasma gondii from Rats (Rattus rattus) in Riyadh, Saudi Arabia.

Toxoplasma 3 main clonal lineages are designated as type I, II, and III; however, atypical and mixed genotypes were also reported. This study was conducted for detection of Toxoplasma gondii genotypes in rats (Rattus rattus) in Riyadh region, Saudi Arabia. PCR test on T. gondii B1 gene was conducted on ELISA IgM positive samples for confirmation of the infection. However, genetic analysis of the SAG2 locus was performed to determine T. gondii genotypes using PCR-RFLP technique. PCR test on T. gondii B1gene showed that 22 (81.5%) out of the 27 ELISA IgM positive samples have T. gondii DNA. Genotypic analysis shows that, of the total 22 PCR positive samples, only 13 (59.1%) were of type II, 7 (31.8%) were of type III, and 2 (9.1%) were of an unknown genotype. It is obvious that the prevalence of both type II and III is high in rats. No reports have been available on T. gondii genotypes among rats in Riyadh region, and only little is known about its seroprevalence in rats. Future studies on T. gondii genotypes in rats using multi-locus markers is needed in Riyadh region, Saudi Arabia for better understanding of T. gondii pathogenesis and treatment in humans and animals.

Genetic characterization of Toxoplasma gondii from cats in Yunnan Province, Southwestern China.

BackgroundCats are the definitive hosts of Toxoplasma gondii. The distribution of genetic diversity of T. gondii in cats is of importance to understand the transmission of this parasite. The objective of this study was to genetically characterize T. gondii isolates from cats in Yunnan province, southwestern China.MethodsGenomic DNA was extracted from 5–10 g cat tissue samples (brain, tongue, heart, and liver). Using multilocous polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology, we determined genetic diversity of T. gondii isolates from cats in Yunnan province.ResultIn total, 175 stray cats were tested for T. gondii DNA, respectively, 44 (25.14%) of which were found to be positive for the T. gondii B1 gene by PCR amplification. The positive DNA samples were typed at 11 genetic markers, including 10 nuclear markers, namely, SAG1, 5'-3'SAG2, alternative SAG2, SAG3, GRA6, L358, PK1, BTUB, c22-8, c29-2 and an apicoplast locus Apico. Of these, 16 isolates from cats were genotyped with data for more than 9 loci, revealed 5 genotypes in total, of which 11 of 16 samples were identified as ToxoDB#9, two samples may belong to genotye #225, one was Type II, one was ToxoDB#3, and one was ToxoDB#20 (http://toxodb.org/toxo/).ConclusionsThe results of the present study indicated a wide distribution of T. gondii infection in cats in Yunnan province, which may pose significant public health concerns. To our knowledge, the present study is the first report of T. gondii prevalence and genotypes in cats in southwestern China, and the first report of Type II T. gondii from cats in China.

Seroprevalence and genetic characterization of Toxoplasma gondii in three species of pet birds in China

BackgroundToxoplasmosis, caused by the protozoan parasite Toxoplasma gondii, is one of the most common zoonosis worldwide, affecting a wide range of warm-blooded mammals and birds worldwide. However, no information on T. gondii infection in pet birds in China is available. Therefore, this study was performed to determine the prevalence of T. gondii infection in pet birds in Gansu province, China.MethodsA total of 687 blood samples were collected from pet birds (Carduelis spinus, Alauda gulgula, Cocothraustes migratorlus) in three representative administrative regions in Gansu province, northwest China between August 2011 and September 2012 T. gondii antibodies were determined using the modified agglutination test (MAT). Genomic DNA was extracted from the brain tissues of seropositive pet birds and T. gondii B1 gene was amplified using a semi-nested PCR.DNA samples giving positive B1 amplification were then genetically characterized using multi-locus PCR-RFLP.ResultsThe overall T. gondii seroprevalence was 11.21% (77/687). C. spinus had the highest T. gondii seroprevalence (11.65%), followed by A. arvensis (11.39%) and C. migratorlus (5.26%), these differences were not statistically significant (P > 0.05). Of 77 DNA samples, 8 were positive for the T. gondii B1 gene, four showed complete genotyping results. Only one genotype (the Type II variant: ToxoDB genotype #3) was identified.ConclusionsThe results of the present survey indicated the presence of T. gondii infection in pet birds in Gansu province, China. These data provide base-line information for the execution of control strategies against T. gondii infection in pet birds. To our knowledge, this is the first report documenting the occurrence of T. gondii prevalence and genotype in pet birds in China.

Presumed toxoplasmic central retinal artery occlusion and multifocal retinitis with perivascular sheathing

Central retinal artery occlusion (CRAO) and multifocal retinitis with perivascular sheathing are rare in ocular toxoplasmosis. We report a case of toxoplasmic CRAO and multifocal retinitis with perivascular sheathing. A healthy 83-year-old male developed left panuveitis. Funduscopic examination of the left eye showed a swollen optic disc and sheathing of the retinal artery with a dense vitreous haze and a white retinal lesion. Serum anti-toxoplasma antibodies were positive in a latex agglutination assay. Vitrectomy was performed to improve visualization of the retinal lesions and for examination of causative microorganisms. A postoperative fundus examination revealed CRAO with optic disc involvement and multifocal retinitis with perivascular sheathing. Qualitative multiplex polymerase chain reaction detected the Toxoplasma gondii B1 gene in ocular fluid from both the aqueous and vitreous humor. The presumed diagnosis of ocular toxoplasmosis was made and treatment was started with prednisone and acetylspiramycin with subsequent improvement. Two months later, the patient developed active retinochoroiditis in the left eye. After 6 weeks of anti-toxoplasma therapy, the disease involuted. Retinal vascular occlusions and multifocal retinitis with perivascular sheathing are rare in toxoplasmosis. This is the first case report of toxoplasmic CRAO and multifocal retinitis with perivascular sheathing. The diagnosis of ocular toxoplasmosis should be considered in patients with retinal artery occlusions and multifocal retinitis with perivascular sheathing associated with inflammation.

Seroprevalence, risk factors and genotyping of Toxoplasma gondii in domestic geese ( Anser domestica ) in tropical China

Little information is available about the seroprevalence of Toxoplasma gondii infection in geese (Anser domestica) in China. In the present investigation, the seroprevalence, risk factors and genotyping of T. gondii in geese were investigated in Hainan province, tropical China. A total of 600 serum samples and 150 brain tissue samples were collected from six administrative regions in tropical China, and assayed for T. gondii antibodies by Indirect Haemagglutination (IHA) test. Genomic DNA was extracted from the 30 brain tissues of seropositive geese and T. gondii B1 gene was amplified using a semi-nested PCR. DNA samples giving positive B1 amplification were then genetically characterized using multi-locus PCR-RFLP. Overall, 17% (95% CI: 14–20) of the animals were positive for T. gondii antibodies. Presence of cats in the household (odds ratio, OR 3), hygiene (OR 2.3) and presence of stray cat around the house (OR 2.3) were considered as main risk factors associated with T. gondii infection. Of 30 DNA samples, three were positive for the T. gondii B1 gene, two showed complete genotyping results. Only one genotype (type II) was identified. The results of the present survey indicated the presence of T. gondii infection in geese in tropical China. Therefore, it is imperative that improved integrated measures be carried out to prevent and control T. gondii infection in geese in this province. This is the first report documenting the occurrence of T. gondii genotype in geese in China.

Genetic characterization of Toxoplasma gondii from Qinghai vole, Plateau pika and Tibetan ground-tit on the Qinghai-Tibet Plateau, China

BackgroundThe distribution of genetic diversity of Toxoplasma gondii in wildlife is of interest to understand the transmission of this parasite in the environment. Limited information on T. gondii genotypes has been reported in wildlife in China. The objective of this study was to carry out the genetic characterization of T. gondii isolates from wild animals on the Qinghai-Tibet Plateau.MethodsUsing PCR and multilocous polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technology, we detected genetic diversity of T. gondii isolates from Qinghai vole, Plateau pika and Tibetan ground-tit in these regions.ResultsIn total, 183 brain tissues of different wild animals, including 48 Qinghai vole (Microtus fuscus), 101 Plateau pika (Ochotona curzoniae) and 34 Tibetan ground-tit (Pseudopodoces humilis), were tested for T. gondii infection. 11 of these were found to be positive for the T. gondii B1 gene by PCR amplification. These positive DNA samples were typed at 10 genetic markers, including 9 nuclear loci (SAG1, 5’-and 3’-SAG2, alternative SAG2, BTUB, GRA6, L358, PK1, c22-8, c29-2), and an apicoplast locus Apico. Six were successfully genotyped at eight or more genetic loci, and were grouped to three distinct genotypes. Four samples belonged to ToxoDB Genotype #10 and the other two samples were identified as two new genotypes (http://toxodb.org/toxo/).ConclusionsTo our knowledge, this is the first report of genetic typing of T. gondii isolates in wildlife on the Qinghai-Tibet Plateau, China. The results show that there is a potential risk for the transmission of this parasite through the wildlife in this region.

Prevalence and Genetic Characterization of Toxoplasma gondii in House Sparrows (Passer domesticus) in Lanzhou, China

The prevalence of Toxoplasma gondii infection in birds has epidemiological significance because birds are indeed considered as a good indicator of environmental contamination by T. gondii oocysts. In this study, the prevalence of T. gondii in 313 house sparrows in Lanzhou, northwestern China was assayed by the modified agglutination test (MAT). Antibodies to T. gondii were positive in 39 (12.46%) of 313 samples (MAT titer ≥ 1:5). Tissues of heart, brain, and lung from the 39 seropositive house sparrows were tested for T. gondii DNA, 11 of which were found to be positive for the T. gondii B1 gene by PCR amplification. These positive DNA samples were typed at 9 genetic markers, including 8 nuclear loci, i.e., SAG1, 5'- and 3'-SAG2, alternative SAG2, SAG3, GRA6, L358, PK1, c22-8 and an apicoplast locus Apico. Of them, 4 isolates were genotyped with complete data for all loci, and 2 genotypes (Type II variants; ToxoDB #3 and a new genotype) were identified. These results showed that there is a potential risk for human infection with T. gondii in this region. To our knowledge, this is the first report of T. gondii seroprevalence in house sparrows in China.

Prevalence of <i>Toxoplasma gondii</i> Infection in Rabbits of Korea by Serological Tests and Nested Polymerase Chain Reaction

ABSTRACT>This study surveyed the Toxoplasma (T.) gondii infection prevalence in the Korean rabbit population. Rabbits (n=142) were obtained from two breeding farms in the Gongju area, Chungnam Province, and in the Kochang area, Junbuk Province, Korea. Of 142 sera samples analyzed by enzyme-linked immunosorbent assay (ELISA), 15 (10.6%) exhibited T. gondii-specific IgG antibodies, and 1 (0.7%) rabbit harbored T. gondii-specific IgM. Female rabbits (9/84; 10.7%) had a similar T. gondii prevalence to males (6/58; 10.3%). When stratified by age, rabbits aged >1 year had a similar prevalence of T. gondii infection (7/66; 10.6%) to rabbits aged <1 year (8/76; 10.5%). Immunoblotting detected 6 major antigenic bands corresponding to T. gondii-positive sera at 20, 28, 30, 35, 63 and 77 kDa. Nested polymerase chain reaction (PCR) of whole-blood samples detected the T. gondii B1 gene in 23 rabbits (16.2%). All PCR-positive samples corresponded to partial T. gondii B1 gene sequences with 99% homology to a T. gondii sequence deposited in GenBank (accession number EU340874). Female rabbits (13/84; 15.5%) harbored a similar prevalence of T. gondii DNA to males (10/58; 17.2%). Rabbits aged >1 year had a similar prevalence (12/66; 18.2%) of T. gondii infection to rabbits aged <1 year (11/76; 14.5%). No statistically significant differences were observed regarding the prevalences of infection according to sex or age using molecular or serological tests. This study is the first survey using serological tests and nested PCR to analyze the T. gondii prevalence in rabbits in Korea.

Sensitive and Cost-Effective Detection of Toxoplasma Gondii in Water Supplies of the Black Sea in Turkey by Loop-Mediated Isothermal Amplification (LAMP)

ABSTRACTDetection of Toxoplasma in water samples was performed by loop-mediated isothermal amplification (LAMP) assay of Toxoplasma gondii B1 gene and nested polymerase chain reaction assays (PCR) of the 18S-rRNA gene. The identification limit (sensitivity) of T. gondii LAMP assay is 100 fg/μL of T. gondii DNA. Thirty randomly selected water pellets were spiked with 10 Toxoplasma oocysts to illustrate the sensitivity of LAMP and nested PCR. When the LAMP assay results were compared with those from the nested PCR, the identification sensitivity in spiked pellets was 100 % by LAMP and 43.33 % by nested PCR. Furthermore, 60 natural water samples of different sources were outright analyzed by LAMP and nested PCR. Twenty-five percent (15/60) and 10 % (6/60) of the natural water samples were positive for Toxoplasma DNA by LAMP and nested PCR, respectively. These data indicate that Toxoplasma contamination can be detected in water samples of Black Sea area in Turkey by LAMP and nested PCR methods.

Serologic Survey of Toxoplasmosis in Seoul and Jeju-do, and a Brief Review of Its Seroprevalence in Korea

Knowledge of the prevalence of human Toxoplasma gondii infection is required in the Republic of Korea. In this study, we surveyed the seroprevalence of T. gondii infection and analyzed the risk factors associated with seropositivity among residents in 2 administrative districts; Seoul and the island of Jeju-do, which have contrasting epidemiologic characteristics. Sera and blood collected from 2,150 residents (1,114 in Seoul and 1,036 in Jeju-do) were checked for IgG antibody titers using ELISA and for the T. gondii B1 gene using PCR. In addition, participants completed a questionnaire that solicited information on gender, age, occupation, eating habits, history of contact with animals, and travel abroad. The T. gondii B1 gene was not detected in all residents examined. However, ELISA showed 8.0% (89 of 1,114 sera) positive for IgG antibodies against T. gondii in Seoul and 11.3% (117 of 1,036 sera) in Jeju-do. In both districts, the positive rates were higher in males than in females, and those 40-79 years of age showed higher rates than other ages. In Seoul, residents older than 70 years of age showed the highest positive rate, 14.9%, whereas in Jeju-do the highest prevalence, 15.6%, was in those in their sixties. The higher seropositive rate in Jeju-do than in Seoul may be related to eating habits and occupations. The present results and a review of related literature are indicative of an increased seroprevalence of T. gondii in Korea in recent years.

Evaluating the Prevalence of Toxoplasma gondii in Meat and Meat Products in Ahvaz by PCR Method

Background: Toxoplasma gondii is an obligate, intracellular parasite, which is widely spread in the world. The parasite is able to infect all warm-blooded hosts including human.The infection occures via consumption of food or water containing oocytes, eatingundercooked meats containing tissue cysts, and placenta. Undercooked meat consumption is one of the most important ways of Toxoplasma transmission especially in pregnancy period. Raw and undercooked meats have been reported responsible for 50 % of congenital toxoplasmosis. Objectives: The current study was conducted to determine the prevalence of T. gondii in lamb and beef, and also meat products by molecular method in Ahvaz,southwest of Iran. Materials and Methods: Totally 190 samples were collected from local retailers in Ahvaz city. Samples of tongue, heart and muscle were taken from 50 lamb and 50 beef distributors and 90 meat product samples (sausages, hamburgers and salami, 30 samples of each). Collected samples were minced by electric meat grinder. DNA was extracted from 190 meat and meat product samples by Qiagen DNA Mini Kit. specific primers for the T. gondii B1 gene was used to detect the parasite in samples, by PCR method. Results: A total of seven lamb out of 50 (14 %) and two beef out of 50 (4 %) were found as positive for T. gondii cyst. The parasite was not isolated from any of the meat product samples. Conclusions: The detection of the parasite in slaughtered animals, indicated that the risk still exists for food-transmitted toxoplasmosis, and consumption of raw or undercooked meat can transmit the infection to human community.

Triplex PCR using new primers for the detection of Toxoplasma gondii

Molecular methods are used increasingly for the detection of Toxoplasma gondii infection. This study developed a rapid, sensitive, and specific conventional triplex PCR for the detection of the B1 gene and ITS1 region of T. gondii using newly designed primers and an internal control based on the Vibrio cholerae HemM gene. The annealing temperature and concentrations of the primers, MgCl2, and dNTPs were optimized. Two sets of primers (set 1 and 2) were tested, which contained different segments of the T. gondii B1 gene, 529 repeat region and ITS1 region. A series of sensitivity tests were performed using parasite DNA, whole parasites, and spiked human body fluids. Specificity tests were performed using DNA from common protozoa and bacteria. The newly developed assay based on set 2 primers was found to be specific and sensitive. The test was capable of detecting as little as 10pg T. gondii DNA, 104 tachyzoites in spiked body fluids, and T. gondii DNA in the organ tissues of experimentally infected mice. The assay developed in this study will be useful for the laboratory detection of T. gondii infection.