scholarly journals Activity of Cefepime in Combination with the novel ß-Lactamase inhibitor taniborbactam (VNRX-5133) against ESBL-producing isolates in in vitro checkerboard assays

Author(s):  
Wendy Kloezen ◽  
Ria J. Melchers ◽  
Panagiota-Christina Georgiou ◽  
Johan W. Mouton ◽  
Joseph Meletiadis

Background. Extended spectrum beta-lactamase (ESBL) producing strains are increasing worldwide limiting therapeutic options. Taniborbactam (VNRX-5133) is a newly developed beta-lactamase inhibitor with a wide spectrum of activity covering both serine and metallo enzymes. We therefore, evaluated cefepime-taniborbactam activity against ESBL-producing isolates and determined the concentrations to be used in MIC determinations in the clinical laboratory. Methods. The in vitro activity of cefepime (0.06-256 mg/l) combined with taniborbactam (0.03-32 mg/l) against 129 clinically and molecularly well-documented ESBL producing isolates (42 Escherichia coli, 39 Klebsiella pneumoniae, 28 Pseudomonas aeruginosa, 16 Enterobacter cloacae, 2 Citrobacter freundii, 2 Enterobacter aerogenes) was tested with a broth microdilution checkerboard method based on ISO standard. The MICs of cefepime alone and in combination together with % of resistance at different concentrations of taniborbactam was calculated for each species and resistance mechanism. Results. The median (range)/MIC90 of cefepime were 32(0.125-256)/256 mg/l for all Enterobacterales isolates (n=101) with 72% being resistant and 32(8-256)/128 mg/l for the 28 P. aeruginosa isolates with 86% being resistant. The median(range)/90th percentile concentration of taniborbactam required to restore Enterobacterales susceptibility to cefepime (MIC ≤1 mg/l) was 0.06(≤0.03-32)/4 mg/l and P. aeruginosa susceptibility to increased exposure to cefepime (MIC ≤8 mg/l) 1(≤0.032-32)/32 mg/l. At a fixed concentration of 4 mg/liter of taniborbactam, cefepime median(range)/MIC90 were reduced to 0.125(0.06-4)/1 mg/l for Enterobacterales with no resistance detected and to 8(2-64)/16 mg/liter for P. aeruginosa isolates where 36% remained resistant. Conclusion. The combination cefepime/taniborbactam demonstrated a potent activity against ESBL isolates restoring susceptibility of all Enterobacterales and 2/3 of P. aeruginosa isolates.

1997 ◽  
Vol 41 (4) ◽  
pp. 721-727 ◽  
Author(s):  
P D Lister ◽  
A M Prevan ◽  
C C Sanders

An in vitro pharmacokinetic model was used to study the pharmacodynamics of piperacillin-tazobactam and piperacillin-sulbactam against gram-negative bacilli producing plasmid-encoded beta-lactamases. Logarithmic-phase cultures were exposed to peak antibiotic concentrations observed in human serum after the administration of intravenous doses of 3 g of piperacillin and 0.375 g of tazobactam or 0.5 g of sulbactam. Piperacillin and inhibitor were either dosed simultaneously or piperacillin was dosed sequentially 0.5 h after dosing with the inhibitor. In studies with all four test strains, the pharmacodynamics observed after simultaneous dosing were similar to those observed with the sequential regimen. Since the ratio between piperacillin and tazobactam was in constant fluctuation after sequential dosing, these data suggest that the pharmacodynamics of the piperacillin-inhibitor combinations were not dependent upon maintenance of a critical ratio between the components. Furthermore, when regrowth was observed, the time at which bacterial counts began to increase was similar between the simultaneous and sequential dosing regimens. Since the pharmacokinetics of the inhibitors were the same for all regimens, these data suggest that the length of time that the antibacterial activity was maintained over the dosing interval with these combinations was dictated by the pharmacokinetics of the beta-lactamase inhibitor in the combination. The antibacterial activity of the combination appeared to be lost when the amount of inhibitor available fell below some critical concentration. This critical concentration varied depending upon the type and amount of enzyme produced, as well as the specific inhibitor used. These results indicate that the antibacterial activity of drug-inhibitor combinations, when dosed at their currently recommended ratios, is more dependent on the pharmacokinetics of the inhibitor than on those of the beta-lactam drug.


2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S782-S782
Author(s):  
Sailaja Puttagunta ◽  
Maya Kahan-Haanum ◽  
Sharon Kredo-Russo ◽  
Eyal Weinstock ◽  
Efrat Khabra ◽  
...  

Abstract Background The prevalence of extended-spectrum beta-lactamase (ESBL) producing and carbapenem resistant (CR) Klebsiella pneumoniae (KP) has significantly risen in all geographic regions. Infections due to these bacteria are associated with high mortality across different infection types. Even with newer options, there remains an unmet need for safe and effective therapeutic options to treat infections caused by ESBL and CR KP. Phage therapy offers a novel approach with an unprecedented and orthogonal mechanism of action for treatment of diseases caused by pathogenic bacterial strains that are insufficiently addressed by available antibiotics. Phage-based therapies confer a high strain-level specificity and have a strong intrinsic safety profile. Here we describe the identification of novel phages that can effectively target antibiotic resistant KP strains. Host range of the 21 phages on 33 strain KP panel via solid culture infectivity assays. Red marks resistance to infection while sensitivity to phage is marked in green Methods KP clinical strains were isolated from human stool specimens preserved in glycerol. Selective culturing was carried, followed by testing of individual colonies for motility, indole and urease production, sequenced and analyzed by Kleborate tool to determine antibiotic resistant genes. Natural phages were isolated from plaques that developed on susceptible bacterial targets, sequenced and characterized. Results Antibiotic-resistant KP strains encoding beta lactamase genes or a carbapenemase (n=33) were isolated from healthy individuals (n=3), and patients with inflammatory bowel disease (n=26) or primary sclerosing cholangitis (n=3). Isolates sequencing revealed bla CTX-M15 and/or bla SHV encoding strains and carbapenamase KPC-2. A panel of 21 phages targeting the beta-lactamase- and carbapenemase-producing KP strains were identified. Phage sequencing revealed that all phages belong to the Caudovirales order and include 6 Siphoviridae, 14 Myoviridae, and 1 Podoviridae. In vitro lytic activity of the phages was tested on the isolated bacteria and revealed a coverage of 70% of the 33 isolated antibiotic resistant strains, >50% of which were targeted by multiple phages. Conclusion Collectively, these results demonstrate the feasibility of identifying phage with potent activity against antibiotic resistant KP strains, and may provide a novel therapeutic approach for treatment of ESBL and CR KP infections. Disclosures All Authors: No reported disclosures


2019 ◽  
Author(s):  
Fabienne Benz ◽  
Jana S. Huisman ◽  
Erik Bakkeren ◽  
Joana A. Herter ◽  
Tanja Stadler ◽  
...  

AbstractHorizontal gene transfer, mediated by conjugative plasmids, is a major driver of the global spread of antibiotic resistance. However, the relative contributions of factors that underlie the spread of clinically relevant plasmids are unclear. Here, we quantified conjugative transfer dynamics of Extended Spectrum Beta-Lactamase (ESBL) producing plasmids in the absence of antibiotics. We showed that clinical Escherichia coli strains natively associated with ESBL-plasmids conjugate efficiently with three distinct E. coli strains and one Salmonella enterica serovar Typhimurium strain, reaching final transconjugant frequencies of up to 1% within 24 hours in vitro. The variation of final transconjugant frequencies varied among plasmids, donors and recipients and was better explained by variation in conjugative transfer efficiency than by variable clonal expansion. We identified plasmid-specific genetic factors, specifically the presence/absence of transfer genes, that influenced final transconjugant frequencies. Finally, we investigated plasmid spread within the mouse intestine, demonstrating qualitative agreement between plasmid spread in vitro and in vivo. This suggests a potential for the prediction of plasmid spread in the gut of animals and humans, based on in vitro testing. Altogether, this may allow the identification of resistance plasmids with high spreading potential and help to devise appropriate measures to restrict their spread.


1995 ◽  
Vol 29 (5) ◽  
pp. 501-514 ◽  
Author(s):  
Lori L Schoonover ◽  
Donna J Occhipinti ◽  
Keith A Rodvold ◽  
Larry H Danziger

Objective: To discuss the antimicrobial activity, pharmacokinetics, clinical efficacy, and adverse effect profile of piperacillin/tazobactam, a new beta-lactam/beta-lactamase inhibitor combination. Data Sources: Literature was identified by MEDLINE search of the medical literature, review of selected references, and data provided by the manufacturer. Study Selection: In vitro susceptibility data were surveyed from studies following the methods of the National Committee for Clinical Laboratory Standards. Data evaluating clinical efficacy were selected from all published trials and abstracts. Additional information concerning safety, chemistry, and pharmacokinetics was reviewed. Data Synthesis: The antimicrobial activity of piperacillin is enhanced by addition of tazobactam against gram-positive, gram-negative, and anaerobic bacteria. Tazobactam is active against a broad spectrum of plasmid and chromosomally mediated enzymes and has minimal ability to induce class I chromosomally mediated beta-lactamase enzymes. Piperacillin/tazobactam's expanded activity appears encouraging in the treatment of mixed aerobic and anaerobic infections. Direct comparisons of ticarcillin/clavulanate and piperacillin/tazobactam for the treatment of lower respiratory tract infections showed piperacillin/tazobactam to be clinically superior, and in the treatment of skin and soft tissue infections the 2 agents were comparable. For the treatment of intraabdominal infections, piperacillin/tazobactam was at least as effective as imipenem/cilastatin and clindamycin plus gentamicin. Conclusions: The combination of tazobactam with piperacillin results in an antimicrobial agent with enhanced activity against most beta-lactamase–producing organisms. Preliminary data indicate that piperacillin/tazobactam has proven clinical efficacy in the treatment of a variety of infections, especially polymicrobic infections.


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