الفهرس 
MorphologyOnly 14 pages are availabe for public view
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Abstract
Toxoplasma gondii is an important apicomplexan parasite of human and other warm-blooded animals. The seroprevalence of T. gondii in human population varies greatly among different countries, geographical areas within the same country, and among the ethnic groups living in the same area.Three routes of transmission are usually considered, ingestion of tissue cysts in the intermediate hosts, ingestion of oocysts shed by the definitive host into the environment and the transplacental crossing of tachyzoites from mother to fetus.The present work was carried out to study the prevalence of toxoplasmosis in pregnant women attending Menoufia hospitals with assessment of the possible risk factors for acquiring this infection. In addition, to evaluate the prevalence in sheep slaughtered for human consumption and to detect Toxoplasma infection in human and animal tissue samples.The study also was carried out to strain characterization of Toxoplasma by using nPCR-RFLP for better understanding the epidemiology of this important parasite.The present study was conducted on both human and animal samples. Regarding human, the study was conducted on 92 women. They were selected from Shebein El Kom Teaching Hospital and Menof General Hospital, Menoufia Governorate. The female patients were divided into 5 groups.Group I consisted of 44 patients presented with first trimester abortion.Group II consisted of 29 patients presented with second trimester abortion.Group III consisted of 7 patients presented with retained dead fetus after 28 weeks gestation (IUFD).Group IV consisted of 6 patients presented with fetus with congenital malformation (CFM).Group V consisted of 6 patients with normal pregnancy outcome for control.Regarding animal, the study was conducted on 180 sheep of different ages and sexes slaughtered for food at Shebein El Kom main abattoir and Menouf abattoir in Menoufia Governorate.In order to study the prevalence and types of Toxoplasma gondii, in both human and animals, the following was done: - Basic data were collected from pregnant women via questionnaires which included information regarding age of the patient, residence, gestational age, gravidity, parity, past occurrence of abortion, IUFD or offspring with congenital anomalies. Questions about contact with cats, contact with soil or gardening, consumption of unwashed raw vegetables or fruits, consumption of undercooked meat and history of blood transfusion or organ transplant were also asked. - Detection of Toxoplasma antibodies in pregnant women (IgG and IgM) and sheep (IgG only) by ELISA. - Samples of muscular tissue taken from the diaphragms and hearts of 18 patches of sheep were digested with acid pepsin solution and the digested material was microscopically examined for bradyzoites of Toxoplasma. - Detection of Toxoplasma DNA in tissue samples of women and sheep by PCR for B1 gene. - Genotyping of T. gondii by nested PCR-RFLP from the present study, the following results were obtained: -Out of 92 patients included in the present study, 52.2% were seropositive for anti-Toxoplasma IgG antibodies and 9.78% were seropositive for anti-Toxoplasma IgM antibodies with an overall prevalence of 57.6% (both IgG and IgM antibodies).-No significant difference between studied groups regarding anti- Toxoplasma IgG and IgM antibodies could be detected. There was a significant association between IgG seroprevalence and age, gravidity, history of abortion, contact with soil and eating under washed vegetables.-In animal, from the 180 tested serum samples of sheep, 99 (55%) were positive for anti-Toxoplasma IgG antibodies. The parasite was detected from 7 patches of muscular tissues out of 18 (38.9%).-Toxoplasma DNA was detected in 26 (28.26%) women by PCR for B1 gene. There was no statistically significant difference between positive and negative PCR regarding age, residence, gravidity, parity or history of bad pregnancy outcomes. There was a significant association between PCR positivity and eating under cooked meat and also eating under washed vegetables.-Based on nPCR-RFLP assay at SAG2 locus, amplification of both ends of the gene was successful in 9 out of 26 (34.6%) positive samples for B1 gene. The nine fully studied samples were characterized as genotype I. In nine of them amplification of SAG2 gene was successful and typed as genotype I. It was noticed that the majority of type I cases presented with first trimester abortion but no correlation between the clinical presentation and the strain genotype I could be detected. No statistical significant association between genotype I and age, residence, gravidity and relevant obstetric history of having abortion, IUFD or CFM could be detected. The genotype I was statistically more prevalent in women having more than two deliveries and in women contacting with soil, however after multivariate analysis these factors were no more significant. - In sheep, none of muscular tissue samples tested showed positive results with PCR for diagnosing toxoplasmosis.