INGEBI   02650
INSTITUTO DE INVESTIGACIONES EN INGENIERIA GENETICA Y BIOLOGIA MOLECULAR "DR. HECTOR N TORRES"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
BM. DIRECT MOLECULAR CHARACTERIZATION AND PLACENTAL TROPISM
Autor/es:
BISIO MM; MOREAU M; RISSO M,; BURGOS JM; LEGUIZAMON S; LEVIN MJ; SEIDENSTEIN ME; SCHIJMAN A.G.
Lugar:
Rosario, Santa Fé, Argentina
Reunión:
Congreso; XII Congreso Argentino de Protozoología y Enfermedades Parasitarias; 2008
Institución organizadora:
Sociedad Argentina de Protozoología
Resumen:
We analyzed the presence of T. cruzi by kDNA PCR in 303 serial peripheral blood
and 49 placental samples from 120 pregnant women with indeterminate Chagas´
disease. To characterize the parasitic population, molecular typing of lineages was
performed by PCR (LgPCR) and minicircle signatures by RFLP-PCR of the 330bp
kDNA amplicons.
The sensitivity of kDNA PCR was 64.5%, reaching 75.5% in serial analyses (3
samples per patient). We classified parasitemias in high (positive findings in all
samples) and low (at least one negative finding).Out of 31 women analyzed, 14
(45,2%) had high parasitemias and 17 (54,8%) low ones. In 14/49 (48.6%)
placental specimens we detected T cruzi. Four of them (28,6%) belonged to
women with high parasitemia and 8 (47,1%) to low ones. Parasite lineages were
identified in 9 bloodstream (8 Tc II and 1 Tc I) and 1 placenta (Tc IId) samples.
Serum samples with negative LgPCR findings were typified by TSSA
serodiagnosis (Trypomastigote small surface antigen). All of them showed a Tc II
infection. RFLP-PCR performed in different samples of the same placenta gave
similar profiles suggesting the presence of the same parasite population. Although
all infecting parasites were Tc II, the bloodstream populations of each patient
presented a patients specific profile during pregnancy.
Conclusions: the clinical sensitivity of PCR increases when serial samples are
tested. Placental parasitism is not necessarily related to high bloodstream
parasitemia. Moreover, women with PCR negative blood but PCR positive
placental specimens could be infected by parasitic strains with placental tropism.T. cruzi by kDNA PCR in 303 serial peripheral blood
and 49 placental samples from 120 pregnant women with indeterminate Chagas´
disease. To characterize the parasitic population, molecular typing of lineages was
performed by PCR (LgPCR) and minicircle signatures by RFLP-PCR of the 330bp
kDNA amplicons.
The sensitivity of kDNA PCR was 64.5%, reaching 75.5% in serial analyses (3
samples per patient). We classified parasitemias in high (positive findings in all
samples) and low (at least one negative finding).Out of 31 women analyzed, 14
(45,2%) had high parasitemias and 17 (54,8%) low ones. In 14/49 (48.6%)
placental specimens we detected T cruzi. Four of them (28,6%) belonged to
women with high parasitemia and 8 (47,1%) to low ones. Parasite lineages were
identified in 9 bloodstream (8 Tc II and 1 Tc I) and 1 placenta (Tc IId) samples.
Serum samples with negative LgPCR findings were typified by TSSA
serodiagnosis (Trypomastigote small surface antigen). All of them showed a Tc II
infection. RFLP-PCR performed in different samples of the same placenta gave
similar profiles suggesting the presence of the same parasite population. Although
all infecting parasites were Tc II, the bloodstream populations of each patient
presented a patients specific profile during pregnancy.
Conclusions: the clinical sensitivity of PCR increases when serial samples are
tested. Placental parasitism is not necessarily related to high bloodstream
parasitemia. Moreover, women with PCR negative blood but PCR positive
placental specimens could be infected by parasitic strains with placental tropism.T cruzi. Four of them (28,6%) belonged to
women with high parasitemia and 8 (47,1%) to low ones. Parasite lineages were
identified in 9 bloodstream (8 Tc II and 1 Tc I) and 1 placenta (Tc IId) samples.
Serum samples with negative LgPCR findings were typified by TSSA
serodiagnosis (Trypomastigote small surface antigen). All of them showed a Tc II
infection. RFLP-PCR performed in different samples of the same placenta gave
similar profiles suggesting the presence of the same parasite population. Although
all infecting parasites were Tc II, the bloodstream populations of each patient
presented a patients specific profile during pregnancy.
Conclusions: the clinical sensitivity of PCR increases when serial samples are
tested. Placental parasitism is not necessarily related to high bloodstream
parasitemia. Moreover, women with PCR negative blood but PCR positive
placental specimens could be infected by parasitic strains with placental tropism.