Thirty-two Trypanosoma cruzi strains, isolated from chronic chagasic patients in the northwest of the state of Paraná (Brazil), were analyzed using molecular, biochemical and biological characteristics. Genotypic analysis using randomly amplified polymorphic DNA and simple sequence repeat-anchored polymerase chain reaction amplified profiles showed a large, genetically well-correlated group that contained the majority of the strains and a divergent group that included the PR-150 strain. For glycoconjugate composition, the PR-150 strain was different from the other strains considering the absence or presence of specific bands in aqueous or detergent phases. This strain was also totally different from the others in one out of the six parameters related to in vitro and in vivo biological behavior. We highlight the fact that the PR-150 was totally resistant to benznidazole. For the other biological parameters this strain was not totally distinct from the others, but it showed a peculiar behavior.

Comparou-se a eficácia de sete agentes químicos, usados na prática odontológica, na descontaminação rápida de 32 cones de guta-percha aderidos com Staphylococcus aureus, Enterococcus faecalis, Escherichia coli ou esporos de Bacillus subtilis. Os cones foram tratados por 1, 5, 10 e 15 minutos com glutaraldeído 2%, hipoclorito de sódio 1%, álcool etílico 70%, álcool-iodado 0,3% e 1%, clorhexidina 2%, água oxigenada 6% e polivinilpirrolidona-iôdo 10%. Cada cone após o tratamento foi transferido para caldo tioglicolato e incubado a 37ºC por 7 dias. Os produtos foram bactericidas após 1 a 5 minutos e esporocidas, com exceção do álcool e do álcool iodado, após 1 a 15 minutos de exposição. Os resultados sugerem que a clorhexidina, o hipoclorito, a polivinilpirrolidona-iôdo, a água oxigenada e o glutaraldeído foram os produtos mais eficazes na descontaminação dos cones de guta-percha.

The effectiveness of seven disinfectant compounds used in dentistry for a rapid decontamination of 32 gutta-percha cones adhered with Staphylococcus aureus, Enterococcus faecalis, Escherichia coli strains or Bacillus subtilis spores was compared. Cones were treated with 2% glutaraldehyde, 1% sodium hypochlorite, 70% ethyl alcohol, 1% and 0.3% iodine alcohol, 2% chlorhexidine, 6% hydrogen peroxide, and 10% polyvinylpyrrolidone-iodine, for 1, 5, 10, and 15 minutes. After treatment, each cone was transferred to thioglycollate broth and incubated at 37ºC for 7 days. The products were bactericidal after 1 to 5 minutes and, with exception of ethyl alcohol and iodine-alcohol, sporicidal after 1 to 15 minutes of exposure. Results suggest that chlorhexidine, sodium hypochlorite, polyvinylpyrrolidone-iodine, hydrogen peroxide, and glutaraldehyde were the most effective products in the decontamination of gutta-percha cones.