In vitro activity of the novel β-lactamase inhibitor taniborbactam (VNRX-5133), in combination with cefepime or meropenem, against MDR Gram-negative bacterial isolates from China

2020 ◽  
Vol 75 (7) ◽  
pp. 1850-1858 ◽  
Author(s):  
Xiaojuan Wang ◽  
Chunjiang Zhao ◽  
Qi Wang ◽  
Zhanwei Wang ◽  
Xinyue Liang ◽  
...  

Abstract Objectives To evaluate in vitro activity of the novel β-lactamase boronate inhibitor taniborbactam (VNRX-5133) combined with cefepime or meropenem against 500 urinary Gram-negative bacilli. Methods Cefepime/taniborbactam and 14 comparators were tested by broth microdilution or agar dilution methods. A total of 450 Enterobacteriaceae and 50 Pseudomonas aeruginosa were selected from 2017 to 2019 based on different β-lactamase-producing or resistance phenotypes. For carbapenem-non-susceptible isolates, the modified carbapenem inactivation method (mCIM), EDTA-CIM (eCIM) and amplification of carbapenemase genes were performed. For NDM-producing isolates and those with cefepime/taniborbactam MICs >8 mg/L, the MICs of meropenem/taniborbactam and/or mutations in PBP3 were investigated. Results Taniborbactam improved cefepime activity with the same efficiency as avibactam improved ceftazidime activity against 66 KPC-2 producers, 30 non-carbapenemase-producing carbapenem-non-susceptible Enterobacteriaceae and 28 meropenem-susceptible P. aeruginosa. However, cefepime/taniborbactam exhibited more potent activity than ceftazidime/avibactam against 56 ESBL-producing, 61 AmpC-producing, 32 ESBL and AmpC co-producing, 87 NDM-producing and 21 MBL-producing Enterobacteriaceae predicted by phenotypic mCIM and eCIM, 82 Enterobacteriaceae that were susceptible to all tested β-lactams and 22 carbapenem-non-susceptible P. aeruginosa. A four-amino acid ‘INYR’ or ‘YRIN’ insertion, with or without a one/two-amino acid mutation in PBP3, may have caused cefepime/taniborbactam MICs >8 mg/L among 96.6% (28/29) of the NDM-5-producing Escherichia coli, which accounted for the majority of isolates with cefepime/taniborbactam MICs >8 mg/L (76.1%, 35/46). Conclusions Taniborbactam’s superior breadth of activity, when paired with cefepime or meropenem, suggests these β-lactam/β-lactamase inhibitor combinations could be promising candidates for treating urinary tract infections caused by ESBL and/or AmpC, KPC or NDM-producing Enterobacteriaceae or P. aeruginosa.

Author(s):  
Meredith A. Hackel ◽  
James A. Karlowsky ◽  
Michele A. Canino ◽  
Daniel F. Sahm ◽  
Nicole E. Scangarella-Oman

Gepotidacin (formerly GSK2140944) is a first in class triazaacenaphthylene antibacterial currently in Phase III clinical trials. When tested against Gram-negative ( n =333) and Gram-positive ( n =225) anaerobes by agar dilution, gepotidacin inhibited 90% of isolates (MIC 90 ) at concentrations of 4 and 2 μg/ml, respectively. Given gepotidacin’s in vitro activity against the anaerobic isolates tested, further study is warranted to better understand gepotidacin’s utility in the treatment of infections caused by clinically relevant anaerobic organisms.


2001 ◽  
Vol 45 (6) ◽  
pp. 1896-1899 ◽  
Author(s):  
Niels Kleinkauf ◽  
Grit Ackermann ◽  
Reiner Schaumann ◽  
Arne C. Rodloff

ABSTRACT The in vitro activity of gemifloxacin was compared to that of other quinolone and nonquinolone antimicrobials against 204 anaerobes by the agar dilution technique. The data indicate that gemifloxacin has a rather selective anaerobic activity. Most Peptostreptococcus, Porphyromonas, and Fusobacterium species are susceptible, while gemifloxacin's activity against other gram-negative anaerobes appears to be variable.


2020 ◽  
Vol 75 (9) ◽  
pp. 2384-2393 ◽  
Author(s):  
Adam G Stewart ◽  
Patrick N A Harris ◽  
Andrew Henderson ◽  
Mark A Schembri ◽  
David L Paterson

Abstract ESBL-producing Enterobacteriaceae as uropathogens have given rise to a sizeable amount of global morbidity. Community and hospital surveillance studies continue to report increasing proportions of these organisms as causes of urinary tract infection (UTI). Due to limited treatment options and the presence of cross-resistance amongst oral antibiotics of different classes, patients often require IV therapy, thereby increasing healthcare costs and reducing the effectiveness of delivering healthcare. Oral cephalosporin antibiotics are well known for their ability to achieve high urinary concentrations, in addition to achieving clinical success for treatment of uncomplicated UTI with a drug-susceptible pathogen. Novel cephalosporin/β-lactamase inhibitor combinations have been developed and demonstrate good in vitro activity against ESBL-producing isolates. A pooled analysis of in vitro activity of existing oral cephalosporin/clavulanate combinations in ESBL-producing Enterobacteriaceae has shown MIC50s of 0.5–1, 0.125–1 and 0.25 mg/L for cefpodoxime, ceftibuten and cefixime, respectively. A novel cyclic boronic acid β-lactamase inhibitor, QPX7728, was able to produce MIC50 values of 0.5 and ≤0.06 mg/L when paired with cefpodoxime and ceftibuten, respectively. Other novel combinations, cefpodoxime/ETX0282 and ceftibuten/VNRX7145, have also demonstrated excellent activity against ESBL producers. Clinical trials are now awaited.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S325-S325
Author(s):  
Meredith Hackel ◽  
Michele A Canino ◽  
Daniel F Sahm ◽  
Nicole Scangarella-Oman

Abstract Background Gepotidacin (GSK2140944) is a first in class novel triazaacenaphthylene bacterial type II topoisomerase inhibitor in clinical development for the treatment of gonorrhea and uncomplicated UTI (acute cystitis). Gepotidacin selectively inhibits bacterial DNA gyrase and topoisomerase IV by a unique mechanism not utilized by any currently approved therapeutic agent and demonstrates in vitro activity against most target pathogens resistant to established antibacterials, including fluoroquinolones. This study assessed the in vitro activity of gepotidacin and comparators against a collection of 649 Gram-positive and Gram-negative anaerobic bacterial clinical isolates. Methods A total of 649 clinically significant Gram-negative (333) and Gram-positive (316) anaerobic clinical isolates previously collected and frozen at −70°C were tested. Isolates came from North America (315/48.5%) and Europe (334/51.5%) and were collected between 2000 and 2017. Minimum inhibitory concentrations (MICs) for gepotidacin and 6 comparators were determined by agar dilution (AD) for all isolates, and by both AD and broth microdilution (BMD) for Bacteroides spp. according to CLSI guidelines (CLSI M11-A8). Most Lactobacillus spp. tested in this study require anaerobic conditions for growth and were tested by anaerobic AD. Results The in vitro activity results of gepotidacin and comparators are shown in the table below. The gepotidacin MIC90 for all Gram-negative anaerobic isolates tested in this study was 4 µg/mL and for the comparators tested was as follows: ceftriaxone 512 μg/mL, clindamycin >8 μg/mL, imipenem 0.5 μg/mL, metronidazole 2 μg/mL, moxifloxacin 8 μg/mL and piperacillin–tazobactam 16 μg/mL. Gepotidacin had the lowest MIC90 (2 μg/mL) for the Gram-positive anaerobic isolates compared with the other antibiotics tested, with the exception of metronidazole (MIC90 = 0.5 µg/mL). Conclusion Gepotidacin showed in vitro activity against a collection of 649 anaerobic Gram-negative and Gram-positive clinical isolates, with an MIC90 value against all Gram-negative anaerobic isolates of 4 µg/mL, and against all Gram-positive anaerobic isolates of 2 µg/mL. Disclosures All authors: No reported disclosures.


2019 ◽  
Vol 74 (10) ◽  
pp. 2934-2937
Author(s):  
Frieder Fuchs ◽  
Axel Hamprecht

Abstract Background Infections caused by carbapenemase-producing Enterobacterales (CPE) constitute a major global health concern and are associated with increased morbidity and mortality. Nitroxoline is an old antibiotic, which has recently been re-launched for the treatment of uncomplicated urinary tract infection. Because of low resistance rates it could be an interesting option for treatment of MDR isolates, yet data on CPE susceptibility are scarce. Objectives To analyse the in vitro activity of nitroxoline against CPE. Methods MICs of nitroxoline were determined by agar dilution for a collection of well-characterized carbapenemase producers (n = 105), producing OXA-48-like (n = 36), VIM (n = 21), IMI (n = 9), IMP (n = 6), NDM (n = 22), KPC (n = 11), OXA-58 (n = 2) and GES (n = 2). For comparison, MICs of ertapenem, imipenem and meropenem were determined by agar gradient diffusion. Results For all 105 isolates, the MIC50/90 of nitroxoline was 8/16 mg/L. All Escherichia coli isolates (30/30, 100%) showed low MICs of 2–8 mg/L and were susceptible to nitroxoline. MICs of 32 mg/L were recorded for five isolates of VIM- and IMI-producing Enterobacter cloacae (n = 3) and OXA- and VIM-producing Klebsiella pneumoniae (n = 2). Conclusions Nitroxoline exhibited excellent in vitro activity against most isolates producing common and rare carbapenemases. If the current EUCAST susceptibility breakpoint of ≤16 mg/L for E. coli in uncomplicated urinary tract infections was applied, 95.2% (100/105) of isolates would be classified as susceptible. Nitroxoline could therefore be an alternative oral option for treatment of uncomplicated urinary tract infections caused by CPE.


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