Biochemical Characterization of Type A and Type B  -Lactamase from Enterobacter cloacae

Then, Rudolf L.; Charnas, Robert L.; Kocher, Hans P.; Manneberg, Michael; Röthlisberger, U; Stocker, Judith

doi:10.1093/clinids/10.4.714

Cited by 8 publications

(4 citation statements)

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“…We confirmed previous observations (Phelps et al, 1986;Then et al, 1988;Nikaido, Liu & Rosenberg, 1990) that the fourth generation cephalosporins had 4-8 fold higher V mUi values but dramatically reduced affinities for E. cloacae chromosomal /Mactamase. Indeed K^ values were nearly four orders of magnitude higher for cefpirome and cefepime than for cefotaxime and ceftriaxone (Table I).…”

Section: P-lactam Hydrolysis and Caknlated Periplasmic Inhibitory Consupporting

confidence: 92%

Factors involved in the enhanced efficacy against Gram-negative bacteria of fourth generation cephalosporins

Hancock

Bellido

1992

Journal of Antimicrobial Chemotherapy

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The fourth generation cephalosporins, cefpirome and cefepime, demonstrate better activity against strains of Enterobacter cloacae with derepressed beta-lactamase than the third generation compounds cefotaxime and ceftriaxone. Several methodological refinements were used to measure the parameters, predicted by the Zimmermann-Rosselet equation to be important in the efficacy of beta-lactams. Outer membrane permeability was measured by a novel HPLC method. The kinetics of interaction of purified beta-lactamase with beta-lactams were estimated to calculate the inhibition and catalytic constants. The periplasmic concentration of beta-lactams leading to growth inhibition of cells was determined by substituting the above parameters into the Zimmermann-Rosselet equation. Consideration of these three factors allowed accurate prediction of MICs in isogenic E. cloacae strains with differing porin or beta-lactamase contents. The fourth generation cephalosporins had markedly reduced affinity for beta-lactamase and increased outer membrane permeability when compared to the third generation cephalosporins. Such advantages were only partly offset by a lower stability of complexes with beta-lactamase and reduced affinity for their targets.

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Section: P-lactam Hydrolysis and Caknlated Periplasmic Inhibitory Consupporting

confidence: 92%

Factors involved in the enhanced efficacy against Gram-negative bacteria of fourth generation cephalosporins

Hancock

Bellido

1992

Journal of Antimicrobial Chemotherapy

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“…Investigators have described more than 190 unique bacterial proteins with the ability to interact with the variety of ␤-lactam-containing molecules that can serve as sub- Seeberg et al (275) divided Enterobacter cloacae cephalosporinases into types A and B on the basis of the pI. Type A strains had similar kinetic properties and were found in the following Enterobacter cloacae strains: 149M, 208, M6300 and 5822M2, whose enzymes have pIs of 8.8 (99,103,134,275,299); GN7471, whose enzyme has a pI of 8.4 (103,192); SC 12629, whose enzyme has a pI of Ͼ9.0 (53). The kinetic data presented here are for enzymes produced by strains 208 (191), V31 (127), and 18SH (97,98) have similar kinetic properties.…”

Section: Introductionmentioning

confidence: 99%

A functional classification scheme for beta-lactamases and its correlation with molecular structure

Bush¹,

Jacoby²,

Medeiros³

1995

Antimicrob Agents Chemother

2,225

1,714

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“…Such strains overproduce the Bush group 1 chromosomal cephatosporinase, which hydrolyzes imipenem (8,9), and also possess an outer membrane of diminished permeability. Such strains overproduce the Bush group 1 chromosomal cephatosporinase, which hydrolyzes imipenem (8,9), and also possess an outer membrane of diminished permeability.…”

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confidence: 99%

Imipenem resistance inEnterobacter

Thomson

Sanders

Chmel

1993

Eur. J. Clin. Microbiol. Infect. Dis.

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Blood cultures obtained on two separate occasions from a 37-year-old male who received multiple antibiotics (including imipenem) for treatment of repeated episodes of intraabdominal abscesses and bacteremia yielded two isolates of Enterobacter with reduced susceptibility to imipenem, extended-spectrum cephalosporins, penicillins and aztreonam. Both isolates were unstable, giving rise to different colony types, each of which produced a single, non-inducible Bush group 1 beta-lactamase (pI = 9.6) that hydrolyzed imipenem. Outer membrane proteins were analyzed but no differences were detected between strains with different levels of imipenem resistance. Three-dimensional tests performed in conjunction with disk diffusion susceptibility tests provided a rapid and convenient means of detecting the production of imipenem-hydrolyzing enzymes by the Enterobacter strains. These isolates provided additional evidence that overproduction of the group 1 cephalosporinase of Enterobacter can contribute to resistance to imipenem.

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Biochemical Characterization of Type A and Type B -Lactamase from Enterobacter cloacae

Cited by 8 publications

References 0 publications

Factors involved in the enhanced efficacy against Gram-negative bacteria of fourth generation cephalosporins

Factors involved in the enhanced efficacy against Gram-negative bacteria of fourth generation cephalosporins

A functional classification scheme for beta-lactamases and its correlation with molecular structure

Imipenem resistance inEnterobacter

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