Resumen

MARTIN, N.G.; CARMONA, O.; GUZMAN BLANCO, M.  y  GRUPO VENEZOLANO DE VIGILANCIA DE LA RESISTENCIA BACTERIANA (GVRB). Effect of ß-lactamases inhibitors on the evolution of resistance to ß-lactams in Gram-negatives bacilli.. Rev. Soc. Ven. Microbiol. [online]. 2002, vol.22, n.1, pp.37-43. ISSN 1315-2556.

The ß-lactams antimicrobial were the first to be used, and today they still are the most frequently used. Among the bacteria responsible of high resistance to ß-lactams are gramnegative rods; the most frequent mechanism is the production of ß-lactamase We follow the trends of resistance of Gram-negative rods to ß-lactams alone and with ß-lactamase-inhibitors during the decade 1988-1998. Since 1988, The Venezuelan Group of Vigilance of the Bacterial Resistance, with 29 health institution in the country; they identify, analyze and publish data on bacteria resistance of isolates from patients with bacterial infection coming from hospitals and the community. It was used diffusion disk, according NCCLS. The software program WHONET (World Health Organization Net) was used. The difference in sensitivity among ß-lactam and ß-lactam/ß-lactamase-inhibitor are: 1. Piperacillin versus piperacillin/tazobactam: between 10 and 30% of resistance for most isolated, except for E. coli (45%) and Serratia sp. (60%). 2. Ampicillin versus ampicillin/sulbactam: between 10 and 30%. 3. Cefoperazone versus Cefoperazone/sulbactam: between 5 and 25%. How is expected gramnegative rods resistance to ß-lactams with a betalactamase-inhibitor (ß-L-I), is lower than the ß-lactam alone; furthermore the difference between them, grows higher with time. This results are relevant, since ß-L-I are described as ß-lactamase inductors.

Palabras clave : ß-lactamasas; ß-lactámicos; bacilos Gram-negativos; resistencia bacteriana; inhibidores de ß-lactamasas; sulbactam; tazobactam.