Chromosomal beta-lactamases of Enterobacter cloacae are responsible for resistance to third-generation cephalosporins.

نویسندگان

  • A H Seeberg
  • R M Tolxdorff-Neutzling
  • B Wiedemann
چکیده

About 70% of all Enterobacter cloacae strains tested possessed one of two species-specific beta-lactamases. These enzymes, E. cloacae beta-lactamase A and E. cloacae beta-lactamase B, with isoelectric points of 8.8 and 7.8, respectively, had the same pH and temperature optima. Both showed similar enzyme kinetics and were inhibited by cloxacillin but not by p-chloromercuribenzoate. E. cloacae beta-lactamase B appeared to be identical with the enzyme of E. cloacae P99. By a mutation in a regulatory gene, inducible enzyme production could be converted into constitutive expression. In E. cloacae, both enzymes did not hydrolyze third-generation cephalosporins, but they were solely responsible for resistance toward these drugs. This was demonstrated by the characterization of Escherichia coli strains expressing an identical resistance pattern after transfer of the corresponding Enterobacter gene.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Resistance in gram-negative bacteria: enterobacteriaceae.

The emergence and spread of resistance in Enterobacteriaceae are complicating the treatment of serious nosocomial infections and threatening to create species resistant to all currently available agents. Approximately 20% of Klebsiella pneumoniae infections and 31% of Enterobacter spp infections in intensive care units in the United States now involve strains not susceptible to third-generation...

متن کامل

Drug resistance, AmpC-β-lactamase and extended-spectrum β-lactamase-producing Enterobacteriaceae isolated from fish and shrimp

The present study aims to detect the production of extended-spectrum beta-lactamases (ESBL) by enterobacteria isolated from samples of fresh shrimp and fish obtained from the retail trade of the city of Sobral, Ceará State, Brazil. All bacterial isolates were submitted to identification and antimicrobial susceptibility testing using aminopenicillin, beta-lactamase inhibitors, carbapenem, 1st, 2...

متن کامل

Affinity of cephalosporins for beta-lactamases as a factor in antibacterial efficacy.

Strains of Escherichia coli, Enterobacter aerogenes, and Enterobacter cloacae that were resistant to ceftazidime (MIC greater than 16 micrograms/ml) but susceptible to BMY 28142 (MIC less than 4 micrograms/ml) were found to contain higher levels of beta-lactamase activity (50- to 3,340-fold) than control strains of the corresponding species. Ceftazidime was at least as resistant as BMY 28142 to...

متن کامل

Dissemination of SHV-12 and characterization of new AmpC-type beta-lactamase genes among clinical isolates of enterobacter species in Korea.

To determine the prevalence and genotype of an extended-spectrum beta-lactamase and new chromosomal AmpC beta-lactamases among clinical isolates of Enterobacter species, we performed antibiotic susceptibility testing, pI determination, induction tests, transconjugation, enterobacterial repetitive consensus (ERIC) PCR, sequencing, and phylogenetic analysis. Among the 51 clinical isolates collect...

متن کامل

Transfer of the chromosomal bla gene from Enterobacter cloacae to Escherichia coli by RP4::mini-Mu.

The resistance gene for beta-lactamase-stable cephalosporins from Enterobacter cloacae was transferred to Escherichia coli by the aid of RP4::mini-Mu. The R-prime plasmids generated carried 60 to 80 kilobases (kb) of E. cloacae DNA and coded for the chromosomal E. cloacae beta-lactamase. The gene was fully expressed in the recipient. Restriction endonuclease EcoRI fragments of the R-prime plasm...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Antimicrobial agents and chemotherapy

دوره 23 6  شماره 

صفحات  -

تاریخ انتشار 1983