Genotoxicity assessment of the antimalarial compound artesunate in somatic cells of mice.

Artesunate is a derivate of artemisinin that is both an antimalarial agent and acts cytotoxically on tumor cells. Despite its therapeutic use, its in vivo genotoxic potential has still not been evaluated. This study, therefore, was an investigation into the effects of a single oral administration of artesunate with an in vivo comet assay that analyzed leukocytes from peripheral blood and liver cells, and a micronucleus (MN) assay of bone marrow cells from male Swiss mice. The artesunate was administered by oral gavage at doses of 5, 50 and 100 mg/kg. Cytotoxicity was assessed by scoring 200 consecutive polychromatic (PCE) and normochromatic (NCE) erythrocytes (PCE/NCE ratio). The results demonstrate that artesunate induced significant DNA damage only in liver cells and that high doses of artesunate caused an increase in the mean number of micronucleated polychromatic erythrocytes (MNPCE). Under our experimental conditions, artesunate showed weak genotoxic effects at low doses and clastogenic effects at high doses. The PCE/NCE ratio indicated no cytotoxicity. The data obtained suggest caution about either continuous or high-dose use of artesunate by humans.

EcoR phylogenetic analysis and virulence genotyping of avian pathogenic Escherichia coli strains and Escherichia coli isolates from commercial chicken carcasses in southern Brazil.

Escherichia coli strains designated as avian pathogenic E. coli (APEC) are responsible for avian colibacillosis, an acute and largely systemic disease that promotes significant economic losses in poultry industry worldwide because of mortality increase, medication costs, and condemnation of carcasses. APEC is a subgroup of extraintestinal pathogenic E. coli pathotype, which includes uropathogenic E. coli, neonatal meningitis E. coli, and septicemic E. coli. We isolated E. coli from commercial chicken carcasses in a Brazilian community and compared by polymerase chain reaction-defined phylogenetic group (A, B1, B2, or D) with APEC strains isolated from sick chickens from different poultry farms. A substantial number of strains assigned to phylogenetic E. coli reference collection group B2, which is known to harbor potent extraintestinal human and animal E. coli pathogens, were identified as APEC (26.0%) in both commercial chicken carcasses and retail poultry meat (retail poultry E. coli [RPEC]) (21.25%). The majority of RPEC were classified as group A (35%), whereas the majority of APEC were groups B1 (30.8) and A (27.6%). APEC and RPEC presented the genes pentaplex, iutA, hly, iron, ompT, and iss, but with different virulence profiles. The similarity between APEC and RPEC indicates RPEC as potentially pathogenic strains and supports a possible zoonotic risk for humans.