Potentiation of #betalactam #antibiotics and β-lactam/β-lactamase inhibitor combinations against #MDR and #XDR #Pseudomonas aeruginosa using non-ribosomal #tobramycin–cyclam conjugates (J Antimicrob Chemother., abstract)

[Source: Journal of Antimicrobial Chemotherapy, full page: (LINK). Abstract, edited.]

Potentiation of β-lactam antibiotics and β-lactam/β-lactamase inhibitor combinations against MDR and XDR Pseudomonas aeruginosa using non-ribosomal tobramycin–cyclam conjugates

Temilolu Idowu, Derek Ammeter, Gilbert Arthur, George G Zhanel, Frank Schweizer

Journal of Antimicrobial Chemotherapy, dkz228, https://doi.org/10.1093/jac/dkz228

Published: 28 May 2019

 

Abstract

Objectives

To develop a multifunctional adjuvant molecule that can rescue β-lactam antibiotics and β-lactam/β-lactamase inhibitor combinations from resistance in carbapenem-resistant Pseudomonas aeruginosa clinical isolates.

Methods

Preparation of adjuvant was guided by structure–activity relationships, following standard protocols. Susceptibility and chequerboard studies were assessed using serial 2-fold dilution assays. Toxicity was evaluated against porcine erythrocytes, human embryonic kidney (HEK293) cells and liver carcinoma (HepG2) cells via MTS assay. Preliminary in vivo efficacy was evaluated using a Galleria mellonella infection model.

Results

Conjugation of tobramycin and cyclam abrogates the ribosomal effects of tobramycin but confers a potent adjuvant property that restores full antibiotic activity of meropenem and aztreonam against carbapenem-resistant P. aeruginosa. Therapeutic levels of susceptibility, as determined by CLSI susceptibility breakpoints, were attained in several MDR clinical isolates, and time–kill assays revealed a synergistic dose-dependent pharmacodynamic relationship. A triple combination of the adjuvant with ceftazidime/avibactam (approved), aztreonam/avibactam (Phase III) and meropenem/avibactam enhances the efficacies of β-lactam/β-lactamase inhibitors against recalcitrant strains, suggesting rapid access of the combination to their periplasmic targets. The newly developed adjuvants, and their combinations, were non-haemolytic and non-cytotoxic, and preliminary in vivo evaluation in G. mellonella suggests therapeutic potential for the double and triple combinations.

Conclusions

Non-ribosomal tobramycin–cyclam conjugate mitigates the effect of OprD/OprF porin loss in P. aeruginosa and potentiates β-lactam/β-lactamase inhibitors against carbapenem-resistant clinical isolates, highlighting the complexity of resistance to β-lactam antibiotics. Our strategy presents an avenue to further preserve the therapeutic utility of β-lactam antibiotics.

Topic: antibiotics – pseudomonas aeruginosa – immunologic adjuvants – pharmaceutical adjuvants – aztreonam – ceftazidime – lactams – ribosomes – infection – tobramycin – meropenem – toxic effect – potentiation – avibactam – carbapenem resistance

Issue Section: ORIGINAL RESEARCH

© The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email: journals.permissions@oup.com.

This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Keywords: Antibiotics; Drugs Resistance; Carbapenem; Beta-lactams; Pseudomonas aeruginosa; Tobramycin; Aztreonam; Avibactam; Ceftazidime.

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Reduced #ceftazidime and #ertapenem susceptibility due to production of #OXA-2 in #Klebsiella pneumoniae ST258 (J Antimicrob Chemother., abstract)

[Source: Journal of Antimicrobial Chemotherapy, full page: (LINK). Abstract, edited.]

Reduced ceftazidime and ertapenem susceptibility due to production of OXA-2 in Klebsiella pneumoniaeST258

Alina Iovleva, Roberta T Mettus, Christi L McElheny, Mustapha M Mustapha, Daria Van Tyne, Ryan K Shields, A William Pasculle, Vaughn S Cooper, Yohei Doi

Journal of Antimicrobial Chemotherapy, dkz183, https://doi.org/10.1093/jac/dkz183

Published: 24 May 2019

 

Abstract

Background

OXA-2 is a class D β-lactamase that confers resistance to penicillins, as well as narrow-spectrum cephalosporins. OXA-2 was recently reported to also possess carbapenem-hydrolysing activity. Here, we describe a KPC-2-encoding Klebsiella pneumoniae isolate that demonstrated reduced susceptibility to ceftazidime and ertapenem due to production of OXA-2.

Objectives

To elucidate the role of OXA-2 production in reduced ceftazidime and ertapenem susceptibility in a K. pneumoniae ST258 clinical isolate.

Methods

MICs were determined by the agar dilution method. WGS was conducted to identify and compare resistance genes between isolates. Expression of KPC-2 was quantified by quantitative RT–PCR and immunoblotting. OXA-2 was expressed in Escherichia coli TOP10, as well as in K. pneumoniae ATCC 13883, to define the relative contribution of OXA-2 in β-lactam resistance. Kinetic studies were conducted using purified OXA-2 enzyme.

Results

K. pneumoniae 1761 belonged to ST258 and carried both blaKPC-2 and blaOXA-2. However, expression of blaKPC-2 was substantially reduced due to an IS1294insertion in the promoter region. K. pneumoniae 1761, K. pneumoniae ATCC 13883 and E. coli TOP10 carrying blaOXA-2-harbouring plasmids showed reduced susceptibility to ertapenem and ceftazidime, but meropenem, imipenem and cefepime were unaffected. blaOXA-2 was carried on a 2910 bp partial class 1 integron containing aacA4-blaOXA-2-qacEΔ1-sul1 on an IncA/C2plasmid, which was not present in the earlier ST258 isolates possessing blaKPC-2 with intact promoters. Hydrolysis of ertapenem by OXA-2 was confirmed using purified enzyme.

Conclusions

Production of OXA-2 was associated with reduced ceftazidime and ertapenem susceptibility in a K. pneumoniae ST258 isolate.

Issue Section: ORIGINAL RESEARCH

© The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email: journals.permissions@oup.com.

This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Keywords: Antibiotics; Drugs Resistance; Beta-lactams; Carbapenem; Ceftazidime; Ertapenem; Meropenem; Imipenem; Cefepime.

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#Ceftazidime – #Avibactam in Combination With #Fosfomycin: A Novel #Therapeutic Strategy Against #MDR #Pseudomonas aeruginosa (J Infect Dis., abstract)

[Source: Journal of Infectious Diseases, full page: (LINK). Abstract, edited.]

Ceftazidime-Avibactam in Combination With Fosfomycin: A Novel Therapeutic Strategy Against Multidrug-Resistant Pseudomonas aeruginosa

Krisztina M Papp-Wallace, Elise T Zeiser, Scott A Becka, Steven Park, Brigid M Wilson, Marisa L Winkler, Roshan D’Souza, Indresh Singh, Granger Sutton, Derrick E Fouts, Liang Chen, Barry N Kreiswirth, Evelyn J Ellis-Grosse, George L Drusano, David S Perlin, Robert A Bonomo

The Journal of Infectious Diseases, jiz149, https://doi.org/10.1093/infdis/jiz149

Published: 17 May 2019

 

Abstract

Previously, by targeting penicillin-binding protein 3, Pseudomonas-derived cephalosporinase (PDC), and MurA with ceftazidime-avibactam-fosfomycin, antimicrobial susceptibility was restored among multidrug-resistant (MDR) Pseudomonas aeruginosa. Herein, ceftazidime-avibactam-fosfomycin combination therapy against MDR P. aeruginosa clinical isolate CL232 was further evaluated. Checkerboard susceptibility analysis revealed synergy between ceftazidime-avibactam and fosfomycin. Accordingly, the resistance elements present and expressed in P. aeruginosa were analyzed using whole-genome sequencing and transcriptome profiling. Mutations in genes that are known to contribute to β-lactam resistance were identified. Moreover, expression of blaPDC, the mexAB-oprM efflux pump, and murA were upregulated. When fosfomycin was administered alone, the frequency of mutations conferring resistance was high; however, coadministration of fosfomycin with ceftazidime-avibactam yielded a lower frequency of resistance mutations. In a murine infection model using a high bacterial burden, ceftazidime-avibactam-fosfomycin significantly reduced the P. aeruginosa colony-forming units (CFUs), by approximately 2 and 5 logs, compared with stasis and in the vehicle-treated control, respectively. Administration of ceftazidime-avibactam and fosfomycin separately significantly increased CFUs, by approximately 3 logs and 1 log, respectively, compared with the number at stasis, and only reduced CFUs by approximately 1 log and 2 logs, respectively, compared with the number in the vehicle-treated control. Thus, the combination of ceftazidime-avibactam-fosfomycin was superior to either drug alone. By employing a “mechanism-based approach” to combination chemotherapy, we show that ceftazidime-avibactam-fosfomycin has the potential to offer infected patients with high bacterial burdens a therapeutic hope against infection with MDR P. aeruginosa that lack metallo-β-lactamases.

Pseudomonas aeruginosa, β-lactams, fosfomycin, combination therapy

Topic:  pseudomonas aeruginosa – ceftazidime – fosfomycin – lactams – infection – mice – avibactam – avibactam/ceftazidime

Issue Section: Major Article

Keywords: Antibiotics; Drugs Resistance; Pseudomonas aeruginosa; Avibactam; Ceftazidime; Fosfomycin.

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Emergence and dominance of #E coli ST131 CTX-M-27 in a community #paediatric cohort study: independent host factors and #bacterial genetic determinants (Antimicrob Agents Chemother., abstract)

[Source: Antimicrobial Agents and Chemotherapy, full page: (LINK). Abstract, edited.]

Emergence and dominance of E. coli ST131 CTX-M-27 in a community paediatric cohort study: independent host factors and bacterial genetic determinants

André Birgy, Corinne Levy, Marie-Hélène Nicolas-Chanoine, Aurélie Cointe, Claire A. Hobson, Mélanie Magnan, Stéphane Bechet, Philippe Bidet, Robert Cohen, Stéphane Bonacorsi

DOI: 10.1128/AAC.00382-19

 

ABSTRACT

The recent emergence and diffusion in the community of Escherichia coli isolates belonging to the multidrug-resistant and CTX-M-27-producing ST131 C1-M27 cluster, makes this cluster potentially as epidemic as the worldwide E coli ST131 subclade C2 composed of multidrug resistant isolates producing CTX-M-15. Thirty-five extended-spectrum beta-lactamase (ESBL) producing ST131 isolates were identified in a cohort of 1,885 French children over a 5 year-period. They were sequenced to characterize the ST131 E. coli isolates producing CTX-M-27 recently emerging in France. ST131 isolates producing CTX-M-27 (n=17), and particularly those belonging to the C1-M27 cluster (n=14), carried many resistance-encoding genes and predominantly a F1:A2:B20 plasmid type. In multivariate analysis, having been hospitalized since birth (OR=10.9; 95%CI=2.4;48.8; p=0.002) and being cared for in a day-care center (OR=9.4;95%; CI=1.5;59.0; p=0.017) were independent risk factors for ST131 CTX-M-27 fecal carriage compared with ESBL-producing non-ST131 isolates. No independent risk factor was found when comparing CTX-M-15 (n=11) and CTX-M-1/14 (n=7)-producing ST131 isolates with ESBL-producing non-ST131 isolates or with non-ESBL-producing isolates. Several factors may contribute to the increase in fecal carriage of CTX-M-27-producing E. coli isolates: resistance to multiple antibiotics, capacity of the CTX-M-27 enzyme to hydrolyze both cefotaxime and ceftazidime, carriage of a peculiar F-type plasmid, and/or capacity to colonize children who have been hospitalized since birth or who attend day-care centers.

Copyright © 2019 American Society for Microbiology. All Rights Reserved.

Keywords: Antibiotics; Drugs Resistance; E. Coli; Pediatrics; Cefotaxime; Ceftazidime.

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Emergence of #ceftazidime – #avibactam- #resistant #Klebsiella pneumoniae during #treatment, #Finland, December 2018 (Euro Surveill., abstract)

[Source: Eurosurveillance, full page: (LINK). Abstract, edited.]

Emergence of ceftazidime-avibactam-resistant Klebsiella pneumoniae during treatment, Finland, December 2018

Kati Räisänen 1, Irma Koivula 2, Heikki Ilmavirta 3, Santeri Puranen 4, Teemu Kallonen 1,5, Outi Lyytikäinen 1, Jari Jalava 1

Affiliations: 1 Department of Health Security, National Institute for Health and Welfare, Helsinki, Finland; 2 Kuopio University Hospital, Unit of Infections and Hospital hygiene, Kuopio University Hospital, Kuopio, Finland; 3 Eastern Finland laboratory Centre, Kuopio, Finland; 4 Aalto University, Department of Computer Science, Espoo, Finland; 5 Department of Biostatistics, University of Oslo, Oslo, Norway

Correspondence:  Kati Räisänen

Citation style for this article: Räisänen Kati, Koivula Irma, Ilmavirta Heikki, Puranen Santeri, Kallonen Teemu, Lyytikäinen Outi, Jalava Jari. Emergence of ceftazidime-avibactam-resistant Klebsiella pneumoniae during treatment, Finland, December 2018. Euro Surveill. 2019;24(19):pii=1900256. https://doi.org/10.2807/1560-7917.ES.2019.24.19.1900256

Received: 24 Apr 2019;   Accepted: 07 May 2019

 

Abstract

In December 2018, a ceftazidime-avibactam (CAZ-AVI)-resistant KPC-2-producing Klebsiella pneumoniae strain was isolated in Finland. CAZ-AVI resistance was observed 34 days after CAZ-AVI treatment in a trauma patient transferred from a hospital in Greece who had been colonised with blaKPC-2-producing K. pneumoniae ST39, and later developed a bloodstream infection. The CAZ-AVI-resistant strain contained a novel 15 amino acid insertion in the KPC-2 protein causing structural changes proximal to the KPC-2 active site.

©   This work is licensed under a Creative Commons Attribution 4.0 International License.

Keywords: Antibiotics; Drugs Resistance; Ceftazidime; Avibactam; Klebsiella pneumoniae; Greece; Finland.

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#ESBLs and #resistance to #ceftazidime / #avibactam and #ceftolozane / #tazobactam combinations in #Escherichia coli and #Pseudomonas aeruginosa (J Antimicrob Chemother., abstract)

[Source: Journal of Antimicrobial Chemotherapy, full page: (LINK). Abstract, edited.]

ESBLs and resistance to ceftazidime/avibactam and ceftolozane/tazobactam combinations in Escherichia coli and Pseudomonas aeruginosa

José-Manuel Ortiz de la Rosa, Patrice Nordmann, Laurent Poirel

Journal of Antimicrobial Chemotherapy, dkz149, https://doi.org/10.1093/jac/dkz149

Published: 23 April 2019

 

Abstract

Objectives

To evaluate the efficacy of the recently launched β-lactam/β-lactamase inhibitor combinations ceftazidime/avibactam and ceftolozane/tazobactam against ESBL-producing Escherichia coli and Pseudomonas aeruginosa strains.

Methods

A series of ESBL-encoding genes (blaTEM, blaSHV, blaCTX-M, blaVEB, blaPER, blaGES and blaBEL) was cloned and expressed in E. coli or P. aeruginosa recipient strains. Cultures of E. coli TOP10 harbouring recombinant plasmids and therefore producing the different ESBLs tested were grown in order to perform measurements of catalytic activities, using benzylpenicillin, ceftazidime and ceftolozane as substrates. IC50s were additionally determined for clavulanic acid, tazobactam and avibactam.

Results

We showed here an overall better activity of ceftazidime/avibactam compared with ceftolozane/tazobactam toward ESBL-producing E. coli and P. aeruginosa. Several ESBLs of the GES, PER and BEL types conferred resistance to ceftolozane/tazobactam in E. coli and P. aeruginosa. For GES-6 and PER-1 producers, resistance to ceftolozane/tazobactam could be explained by a high hydrolysis of ceftolozane and a low activity of tazobactam as an inhibitor. On the other hand, PER-producing P. aeruginosa also exhibited resistance to ceftazidime/avibactam.

Conclusions

Altogether, the results show that the ESBL PER-1, which is widespread worldwide, may be a source of resistance to both ceftolozane/tazobactam and ceftazidime/avibactam. Excellent activity of ceftazidime/avibactam was highlighted for both ESBL-producing E. coli and ESBL-producing P. aeruginosa.

Issue Section: ORIGINAL RESEARCH

© The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email: journals.permissions@oup.com.

This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Keywords: Antibiotics; Drugs Resistance; E. Coli; Pseudomonas aeruginosa; Ceftazidime; Avibactam; Ceftolozane; Tazobactam.

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#Reversal of #carbapenemase-producing #Klebsiella pneumoniae #epidemiology from blaKPC- to blaVIM-harbouring isolates in a #Greek #ICU after introduction of #ceftazidime/avibactam (J Antimicrob Chemother., abstract)

[Source: Journal of Antimicrobial Chemotherapy, full page: (LINK). Abstract, edited.]

Reversal of carbapenemase-producing Klebsiella pneumoniae epidemiology from blaKPC- to blaVIM-harbouring isolates in a Greek ICU after introduction of ceftazidime/avibactam

Matthaios Papadimitriou-Olivgeris, Christina Bartzavali, Anastasia Lambropoulou, Anastasia Solomou, Ekaterini Tsiata, Evangelos D Anastassiou, Fotini Fligou, Markos Marangos, Iris Spiliopoulou, Myrto Christofidou

Journal of Antimicrobial Chemotherapy, dkz125, https://doi.org/10.1093/jac/dkz125

Published: 19 April 2019

 

Abstract

Objectives

Our aim was to determine the epidemiology of bloodstream infections (BSIs) by carbapenemase-producing Klebsiella pneumoniae (CP-Kp) after the introduction of ceftazidime/avibactam in January 2018 among ICU patients.

Patients and methods

All patients hospitalized at the ICU of the University General Hospital of Patras, Greece with CP-Kp BSI during 2015–18 were included. MICs of meropenem, fosfomycin, tigecycline and ceftazidime/avibactam (only for isolates from 2018) were determined by Etest, whereas for colistin, the broth microdilution method was applied. All isolates were tested by PCR for the presence of blaKPC, blaVIM, blaNDM and blaOXA-48 genes.

Results

Among 170 BSIs due to CP-Kp (2015–18), 132 (78%) were caused by isolates carrying blaKPC (4 ceftazidime/avibactam-resistant), 17 blaVIM (10%), 16 blaNDM (9%) and 5 carrying both blaKPC and blaVIM (3%). From 2015 to 2017 (125 BSIs), KPC-producing strains (110; 88%) predominated, followed by NDM-producing strains (15; 12%), whereas no VIM-producing strain was isolated. Among the 45 BSIs in 2018, 22 (49%) were due to isolates carrying blaKPC (4 ceftazidime/avibactam resistant), followed by 17 (38%) carrying blaVIM, 5 (11%) carrying both blaKPC and blaVIM, and 1 isolate carrying blaNDM (2%). MBLs were more frequent in 2018 compared with 2015–17 (51% versus 12%; P < 0.001). Multivariate analysis found that prior administration of ceftazidime/avibactam (P = 0.014; OR 16.7, 95% CI 1.8–158.6) was independently associated with the development of BSI due to ceftazidime/avibactam-resistant isolates.

Conclusions

Widespread ceftazidime/avibactam use may lead to a change in the palette of carbapenemases by replacing KPC with MBL-producing isolates.

Issue Section: ORIGINAL RESEARCH

© The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email: journals.permissions@oup.com.

This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)

Keywords: Antibiotics; Drugs Resistance; Ceftazidime; Avibactam; NDM; ICU; Greece; Klebsiella pneumoniae.

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