title: [Efficiency of tazobactam as inhibitor of beta-lactamases, combined with piperacillin, against resistant strains to this penicillin].
abstract: We studied the efficacy of tazobactam (YTR 830), a new beta-lactamase inhibitor in combination with piperacillin (P) against 198 Enterobacteriaceae strains. A comparative study of susceptibility (MIC determined on Mueller Hinton agar; inoculum 10(4) cfu) was made with the combination amoxicillin (A) + clavulanic acid (CA). Of 181 strains resistant to P, 79.56% were susceptible to it in the presence of tazobactam (TZ). The characteristics of the beta-lactamases of 37 strains resistant to P + TZ (MIC greater than 40 micrograms/ml) were studied; 11 were hyperproducers of chromosomic beta-lactamase and 7 produced two types of plasmidic beta-lactamase. The MICs of TZ alone were uniform and high (64-128 micrograms/ml), independently of the characteristics of the strains beta-lactamase. Of 17 strains susceptible to P, the efficacy of P + TZ was significant among carriers of plasmidic beta-lactamase; there was practically no change in the P susceptibility among the non carriers. The efficacy of P + TZ was similar to that of A + AC against E. coli strains; it was higher against strains of Enterobacter, Citrobacter and Serratia.
authors.forename: C
authors.initials: C
authors.lastname: Roy
authors.forename: M
authors.initials: M
authors.lastname: Tirado
authors.forename: D
authors.initials: D
authors.lastname: Teruel
authors.forename: R
authors.initials: R
authors.lastname: Reig
authors.forename: M
authors.initials: M
authors.lastname: Ràfols
mesh_terms: D000658:Amoxicillin / Q000494:pharmacology; D055598:Chemical Phenomena; D002621:Chemistry; D002969:Clavulanic Acids / Q000494:pharmacology; D004341:Drug Evaluation; D004359:Drug Therapy, Combination / Q000494:pharmacology; D004755:Enterobacteriaceae / Q000187:drug effects*; D005260:Female; D008826:Microbial Sensitivity Tests; D010397:Penicillanic Acid / Q000494:pharmacology*; D010403:Penicillin Resistance; D010878:Piperacillin / Q000494:pharmacology*; D000078142:Tazobactam; D001618:beta-Lactamases / Q000494:pharmacology*
chemical_list: D002969:Clavulanic Acids; D000658:Amoxicillin; D010397:Penicillanic Acid; D001618:beta-Lactamases; D000078142:Tazobactam; D010878:Piperacillin
vernacular_title: Eficacia del tazobactam como inhibidor de betalactamasas, asociado a la piperacilina, frente a cepas resistentes a esta penicilina.