8 research outputs found
High proportion of hepatitis C virus genotypes 1 and 3 in a large cohort of patients from Southern Brazil
Hepatitis C virus (HCV) isolates have been divided into six genotypes
(1 to 6). The duration of hepatitis C standard treatment is 48 weeks
for patients infected with HCV genotype 1 vs 24 weeks for those
infected with genotypes 2 and 3. A total of 1544 HCV isolates from
chronic patients living in the southern Brazilian states of Rio Grande
do Sul (RS, n = 627) and Santa Catarina (SC, n = 917) were genotyped by
restriction fragment length polymorphism (RFLP) of polymerase chain
reaction (PCR) products. In RS, 338 (53.9%; 95% CI 50.0 - 57.8%), 34
(5.4%; 95% CI 3.8 - 7.4%) and, 255 (40.7%; 95% CI 36.9 - 44.6%) samples
were from genotypes 1, 2, and 3, respectively. In SC, 468 (51%; 95% CI
47.8 - 54.2%), 26 (2.9%; 95% CI 1.9 - 4.1%) and, 423 (46.1%; 95% CI
42.9 - 49.3%) samples were from genotypes 1, 2, and 3, respectively.
Genotyping results were confirmed by direct nucleotide sequencing of
PCR products derived from 68 samples, without any discrepancy between
PCR-RFLP and nucleotide sequencing methods. In conclusion, almost half
of the hepatitis C patients from South of Brazil are infected by
genotypes 2 and 3 and, these results have important consequential
therapeutic implications as they can be treated for only 24 weeks, not
48
Characterization of Trypanosoma cruzi Strains Isolated from Chronic Chagasic Patients, Triatomines and Opossums Naturally Infected from the State of Rio Grande do Sul, Brazil
Thirty-five Trypanosoma cruzi strains were isolated from chronic chagasic patients, triatomines and opossums from different municipalities of the State of Rio Grande do Sul. Parasites were characterized by means of mice infectivity, enzyme electrophoresis and randomly amplified polymorphic DNA (RAPD) analysis. Twenty-nine strains were isolated from chagasic patients, 4 from triatomines (2 from Triatoma infestans and 2 from Panstrongylus megistus) and 2 from opossums Didelphis albiventris. Thirty-three T. cruzi strains were of low and 2 strains of high virulence in mice. Both virulent strains were isolated from P. megistus. Isoenzyme analysis of the strains showed 3 different zymodemes. Eleven strains isolated from chagasic patients and 2 from D. albiventris were Z2. Eighteen strains from patients and 2 from T. infestans were ZB and 2 T. cruzi strains isolated from P. megistus were Z1. RAPD profiles obtained with 4 random primers showed a high genetic heterogeneity of the T. cruzi strains. Zymodeme 2 and ZB strains were the more polymorphic. A band sharing analysis of the RAPD profiles of Z2 and ZB strains using 3 primers, showed a very low percentage of shared bands, 20% among 13 ZB strains and 14% among 13 Z2 strains. According to the isoenzyme results, 3 T. cruzi populations were present in State of Rio Grande do Sul. Zymodeme 2 and ZB strains were found infecting man (domiciliar transmission cycle) whereas Z1 strains were found infecting the sylvatic vector P. megistu