Resistance to cefoperazone-sulbactam in Klebsiella pneumoniae: evidence for enhanced resistance resulting from the coexistence of two different resistance mechanisms

Rice, Louis B.; Carias, Lenore L.; Etter, L; Shlaes, David M.

doi:10.1128/aac.37.5.1061

Cited by 24 publications

(13 citation statements)

References 18 publications

(18 reference statements)

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“…However, in many cases the exact nature of the protein has not been established, and the assumption that the involved proteins were porins were largely based on their molecular masses. This has been the case for several reports concerning K. pneumoniae (31,36,47).…”

Section: Discussionmentioning

confidence: 52%

In vivo selection of porin-deficient mutants of Klebsiella pneumoniae with increased resistance to cefoxitin and expanded-spectrum-cephalosporins

Martı́nez-Martı́nez

Hernández-Allés

Albertí

et al. 1996

Antimicrob Agents Chemother

208

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Four Klebsiella pneumoniae isolates (LB1, LB2, LB3, and LB4) with increased antimicrobial resistance were obtained from the same patient. The four isolates were indistinguishable in biotype, plasmid content, lipopolysaccharide, and DNA analysis by pulse-field gel electrophoresis. Isolate LB1 made TEM-1 and SHV-1 beta-lactamases. Isolates LB2, LB3, and LB4 produced SHV-5 in addition to TEM-1 and SHV-1. MICs of cefoxitin, ceftazidime, and cefotaxime against LB1 were 4, 1, and 0.06 micrograms/ml, respectively. MICs of ceftazidime against K. pneumoniae LB2, LB3, and LB4 were > 256 micrograms/ml, and those of cefotaxime were 2, 4, and 64 micrograms/ml, respectively. MICs of cefoxitin against K. pneumoniae LB2 and LB3 were 4 micrograms/ml, but that against K. pneumoniae LB4 was 128 micrgrams/ml. K. pneumoniae LB4 could transfer resistance to ceftazidime and cefotaxime, but not that to cefoxitin, to Escherichia coli. Isolate LB4 and cefoxitin-resistant laboratory mutants lacked an outer membrane protein of about 35 kDa whose molecular mass, mode of isolation, resistance to proteases, and reaction with a porin-specific antiserum suggested that it was a porin. MICs of cefoxitin and cefotaxime reverted to 4 and 2 micrograms/ml, respectively, when isolate LB4 was transformed with a gene coding for the K. pneumoniae porin OmpK36. We conclude that the increased resistance to cefoxitin and expanded-spectrum cephalosporins of isolate LB4 was due to loss of a porin channel for antibiotic uptake.

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Section: Discussionmentioning

confidence: 52%

In vivo selection of porin-deficient mutants of Klebsiella pneumoniae with increased resistance to cefoxitin and expanded-spectrum-cephalosporins

Martı́nez-Martı́nez

Hernández-Allés

Albertí

et al. 1996

Antimicrob Agents Chemother

208

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“…Later, the selection of a porin-deficient mutant in a patient treated with cefoxitin was reported by the same group (274). During the 1990s, in vitro selection of porin mutants by cefoperazone-sulbactam (275) or cefoxitin (276) was confirmed, and clinical porin-deficient isolates resistant to cefoxitin and extended-spectrum cephems (277,278) were reported. Porin loss is often caused by the insertion of an insertion sequence (IS) element (279).…”

Section: Klebsiella Pneumoniaementioning

confidence: 90%

The Challenge of Efflux-Mediated Antibiotic Resistance in Gram-Negative Bacteria

2015

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SUMMARY The global emergence of multidrug-resistant Gram-negative bacteria is a growing threat to antibiotic therapy. The chromosomally encoded drug efflux mechanisms that are ubiquitous in these bacteria greatly contribute to antibiotic resistance and present a major challenge for antibiotic development. Multidrug pumps, particularly those represented by the clinically relevant AcrAB-TolC and Mex pumps of the resistance-nodulation-division (RND) superfamily, not only mediate intrinsic and acquired multidrug resistance (MDR) but also are involved in other functions, including the bacterial stress response and pathogenicity. Additionally, efflux pumps interact synergistically with other resistance mechanisms (e.g., with the outer membrane permeability barrier) to increase resistance levels. Since the discovery of RND pumps in the early 1990s, remarkable scientific and technological advances have allowed for an in-depth understanding of the structural and biochemical basis, substrate profiles, molecular regulation, and inhibition of MDR pumps. However, the development of clinically useful efflux pump inhibitors and/or new antibiotics that can bypass pump effects continues to be a challenge. Plasmid-borne efflux pump genes (including those for RND pumps) have increasingly been identified. This article highlights the recent progress obtained for organisms of clinical significance, together with methodological considerations for the characterization of MDR pumps.

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“…K. pneumoniae 15571 was a clinical isolate from the urinary tract of an infected adult patient. K. pneumoniae 44NR and 44NRF have been described previously (18). In the prior publication, K. pneumoniae 44NR was described in the text as producing "no ␤-lactamase."…”

Section: Methodsmentioning

confidence: 99%

High-Level Expression of Chromosomally Encoded SHV-1 β-Lactamase and an Outer Membrane Protein Change Confer Resistance to Ceftazidime and Piperacillin- Tazobactam in a Clinical Isolate of Klebsiella pneumoniae

Rice¹,

Carias²,

Hujer³

et al. 2000

Antimicrob Agents Chemother

124

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We describe Klebsiella pneumoniae 15571, a clinical isolate resistant to ceftazidime MIC ‫؍‬ 32 g/ml) and piperacillin-tazobactam (MICs ‫؍‬ 1,024 and 128 g/ml). K. pneumoniae 15571 expresses a single ␤-lactamase with a pI of 7.6. However, when cloned in a high-copy-number vector in Escherichia coli, this bla SHV-1 gene did not confer resistance to ceftazidime, a spectrum consistent with the nucleotide sequence, which was nearly identical to those of previously described bla SHV-1 genes. Outer membrane protein (OMP) analysis of K. pneumoniae 15571 revealed a decrease in the quantity of a minor 45-kDa OMP in comparison to that in K. pneumoniae 44NR, a low-level ampicillin-resistant strain that also expresses a chromosomally determined bla SHV-1 . Crude ␤-lactamase enzyme extracts from K. pneumoniae 15571 produced roughly 200-fold more ␤-lactamase activity than K. pneumoniae 44NR. Northern hybridization analysis revealed that this difference was explainable by quantifiable differences in transcription of the bla SHV-1 gene in the two strains. Primer extension analysis of bla SHV-1 mRNA from K. pneumoniae 15571 and 44NR indicated that the transcriptional start sites were identical in the two strains. DNA sequencing of the promoter regions upstream of the of bla SHV-1 open reading frames in the two K. pneumoniae strains revealed an A3C change in the second position of the ؊10 region in K. pneumoniae 44NR compared to that in 15571. Site-directed mutagenesis of the cloned K. pneumoniae 15571 bla SHV-1 , in which the A in the second position of the 15571 ؊10 region was changed to a C, resulted in a substantial lowering of the MIC of ampicillin. When the levels of ␤-lactamase enzyme expression in E. coli were compared, the bla SHV-1 downstream of the altered ؊10 region produced 17-fold less ␤-lactamase enzyme. These results indicate that elevated levels of ceftazidime resistance can result from a combination of increased enzyme production and minor OMP changes and that levels of chromosomally encoded SHV-1 ␤-lactamase production can vary substantially with a single-base-pair change in promoter sequence.Resistance to ceftazidime in Klebsiella pneumoniae is most commonly attributed to the production of plasmid-mediated extended-spectrum ␤-lactamases (ESBLs). These enzymes are frequently encoded by multidrug resistance conjugative plasmids and evolve from the more common TEM-1 and SHV-1 penicillinases through point mutations in regions important for ␤-lactam binding and/or hydrolysis (10). Conjugative dissemination of ESBL-encoding plasmids is thought to facilitate the spread of resistance in the clinical setting. In rare cases, resistance to ceftazidime has been attributed solely to increased production of SHV-1, although MICs of ceftazidime for these strains are only mildly increased (ca. 8 g/ml) (15).Resistance to ␤-lactam-␤-lactamase inhibitor combinations occurs most commonly in gram-negative bacilli through the overproduction of common plasmid-mediated enzymes (20). Overproduction has been attributed to altered promot...

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Resistance to cefoperazone-sulbactam in Klebsiella pneumoniae: evidence for enhanced resistance resulting from the coexistence of two different resistance mechanisms

Abstract: We investigated the in vitro activity and the in vivo efficacy of the 13-lactam-13- pneumoniae.

Cited by 24 publications

References 18 publications

In vivo selection of porin-deficient mutants of Klebsiella pneumoniae with increased resistance to cefoxitin and expanded-spectrum-cephalosporins

In vivo selection of porin-deficient mutants of Klebsiella pneumoniae with increased resistance to cefoxitin and expanded-spectrum-cephalosporins

The Challenge of Efflux-Mediated Antibiotic Resistance in Gram-Negative Bacteria

High-Level Expression of Chromosomally Encoded SHV-1 β-Lactamase and an Outer Membrane Protein Change Confer Resistance to Ceftazidime and Piperacillin- Tazobactam in a Clinical Isolate of Klebsiella pneumoniae

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