. PCR-based screening and lineage identification of Trypanosoma cruzi directly from faecal samples of triatomine bugs from northwestern Argentina.

MARCET, P.L., DUFFY, T., CARDINAL, M.V., LAURICELLA, M., LEVIN, M.J., KITRON, U., GÜRTLER R.E., SCHIJMAN, A.G.

PARASITOLOGY

Cambridge University Express

Año: 2006 vol. 132 p. 57 - 65

0031-1820

This study applied improved DNA extraction and polymerase chain reaction strategies for screening and identi.cation of Trypanosoma cruzi lineages directly from faeces of triatomines collected in a well-de.ned rural area in northwestern Argentina. Ampli.cation of the variable regions of the kinetoplastid minicircle genome (kDNA-PCR) was performed in faecal lysates from 33 microscope (MO)-positive and 93 MO-negative Triatoma infestans, 2 MO-positive and 38 MO-negative Triatoma guasayana and 2 MO-positive and 73 MO-negative Triatoma garciabesi. kDNA-PCR detectedlineages directly from faeces of triatomines collected in a well-de.ned rural area in northwestern Argentina. Ampli.cation of the variable regions of the kinetoplastid minicircle genome (kDNA-PCR) was performed in faecal lysates from 33 microscope (MO)-positive and 93 MO-negative Triatoma infestans, 2 MO-positive and 38 MO-negative Triatoma guasayana and 2 MO-positive and 73 MO-negative Triatoma garciabesi. kDNA-PCR detectedTriatoma infestans, 2 MO-positive and 38 MO-negative Triatoma guasayana and 2 MO-positive and 73 MO-negative Triatoma garciabesi. kDNA-PCR detectedTriatoma guasayana and 2 MO-positive and 73 MO-negative Triatoma garciabesi. kDNA-PCR detected T. cruzi in 91% MO-positive and 7.5% MO-negative T. infestans, which were con.rmed by ampli.cation of the minicircle conserved region. In contrast, kDNA-PCR was negative in all faecal samples from the other triatomine species. A panel of PCR-based genomic markers (intergenic region of spliced-leader DNA, 24Sa and 18S rRNA genes and A10 sequence) was implemented to identify the parasite lineages directly in DNA lysates from faeces and culture isolates from 28 infected specimens. Two were found to be infected with TCI, 24 with TCIIe, 1 with TCIId and 1 revealed a mixed TCI+TCII infection in the faecal sample whose corresponding culture only showed TCII, providing evidence of the advantages of direct typing of biological samples. This study provides an upgrade in the current diagnosis and lineage identi.cation ofin 91% MO-positive and 7.5% MO-negative T. infestans, which were con.rmed by ampli.cation of the minicircle conserved region. In contrast, kDNA-PCR was negative in all faecal samples from the other triatomine species. A panel of PCR-based genomic markers (intergenic region of spliced-leader DNA, 24Sa and 18S rRNA genes and A10 sequence) was implemented to identify the parasite lineages directly in DNA lysates from faeces and culture isolates from 28 infected specimens. Two were found to be infected with TCI, 24 with TCIIe, 1 with TCIId and 1 revealed a mixed TCI+TCII infection in the faecal sample whose corresponding culture only showed TCII, providing evidence of the advantages of direct typing of biological samples. This study provides an upgrade in the current diagnosis and lineage identi.cation ofa and 18S rRNA genes and A10 sequence) was implemented to identify the parasite lineages directly in DNA lysates from faeces and culture isolates from 28 infected specimens. Two were found to be infected with TCI, 24 with TCIIe, 1 with TCIId and 1 revealed a mixed TCI+TCII infection in the faecal sample whose corresponding culture only showed TCII, providing evidence of the advantages of direct typing of biological samples. This study provides an upgrade in the current diagnosis and lineage identi.cation of+TCII infection in the faecal sample whose corresponding culture only showed TCII, providing evidence of the advantages of direct typing of biological samples. This study provides an upgrade in the current diagnosis and lineage identi.cation of T. cruzi in .eld-collected triatomines and shows T. cruzi II strains as predominant in the region. Key words: Trypanosoma cruzi, Triatoma infestans, Triatoma guasayana, Triatoma garciabesi, Chagas disease, PCR, lineage.in .eld-collected triatomines and shows T. cruzi II strains as predominant in the region. Key words: Trypanosoma cruzi, Triatoma infestans, Triatoma guasayana, Triatoma garciabesi, Chagas disease, PCR, lineage.Trypanosoma cruzi, Triatoma infestans, Triatoma guasayana, Triatoma garciabesi, Chagas disease, PCR, lineage.