RESUMO
To investigate the potential of poultry products as the source of human infections associated with quinolone-resistant campylobacters, 140 human and 75 poultry isolates of nalidixic acid-resistant campylobacters were collected between 1996 and 1998, and analysed by two molecular typing methods. By the analysis of restriction fragment length polymorphism of the flagellin gene, 33 distinct patterns were obtained, with 18 of which shared by both human (89%) and poultry (93%) isolates. By the pulsed-field gel electrophoresis of SmaI-restricted macrofragments, 105 different profiles were obtained, and 11 were found in both human (40%) and poultry (23%) isolates. When the two typing methods were combined, 112 unique genotypes were obtained, 11 of which were shared by both populations, including 53 (38%) human isolates and 14 (19%) poultry isolates. Although domestic poultry products are still important sources of the quinolone-resistant campylobacter infections in humans, there are other factors that might contribute to these increasing infections simultaneously. A more stringent policy in the use of antimicrobial agents in food animals can no longer be ignored.
Assuntos
Anti-Infecciosos/farmacologia , Campylobacter/genética , Eletroforese em Gel de Campo Pulsado/métodos , Flagelina/genética , Ácido Nalidíxico/farmacologia , Aves Domésticas/microbiologia , Animais , Campylobacter/classificação , Campylobacter/isolamento & purificação , Farmacorresistência Bacteriana , Humanos , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de RestriçãoRESUMO
The simian virus 40 (SV40) small t (t) antigen is known to be able to induce cell proliferation and to enhance the transforming activity of SV40 large T antigen. Here we report that t could also enhance the transforming activity of v-src oncogene. When t was transfected into the v-src-transformed NIH3T3 cells, the t-expressing stable clones grew faster and grew to higher density than did the parental or vector-transfected cells. Furthermore, these t-expressing cells also showed better plating efficiency and grew more efficiently in soft agar than did the parental or vector-transfected cells. More importantly, the t-expressing cells displayed high tendency to aggregate and detached easily from the dishes, while the parental or vector-transfected cells never exhibited such phenotype. This last observation suggests that t may affect the expression of adhesion molecules in the v-src-transformed NIH3T3 cells. Taken together, we concluded that t could enhance the transforming activity of v-src and alter the transformed morphology of v-src-transformed NIH3T3 cells.
