Plasmidos de virulencia

Abstract

Se revisan conceptos bisicos sobre los plasmidosdesoxirribonucleico extracromosomico con mplicacion autonoma— prisentee en el citoplasma bacte. riano. Se hace infasis en plismidos qua codifican factor's de virulencia como la re-sistencia a las drogas y Ia produccion de enterotoxinas. Sa describen tecnices de laboratorio pare el estudio de plasmidos, tales como la conjugaciOn bacteriana in vitro, electroforesis in gel de agarosa y Ia microscopia electrenica.Las tecnicas permiten determiner Ia transmisibilidad, flamer°, tamalio, forma y peso molecular de los plasmidos.

Basic concepts on plasmids —rings of extrachromosomic deoxyribonucleic acid with autonomous replication— present in the cytoplasm are reviewed. Emphasis is made on plasmids coding for virulence factors such as drug resistance and enterotoxin production. Laboratory techniques for the study of plasmids are described. These are: bacterial conjugation in vitro, agarose gel electrophoresis and electron microscopy. Techniques permit determination of transmissibility, size, form and molecular weight of plasmids