[Current aspects of bacterial resistance to antibiotics]

New aspects of the evolution of bacterial antibiotic resistance are discussed. Dissemination of antibiotic resistance appears to be unlimited since resistance genes from Gram-positive cocci have been detected in Gram negative bacteria. This suggests the occurrence of heterogramic genetic transfers between these phylogenetically distinct organisms. New characters of resistance to beta-lactam antibiotics in enterobacteria result from the apparition of mutant of the TEM-1 and TEM-2 penicillinases. Mutations that confer the capacity to hydrolyze the third generation cephalosporins are located in the active site of the enzymes.