In-vitro activity of the novel oxa-β-lactam antibiotic moxalactam (LV 127935) against dense populations of selected Gram-negative bacilli

1981 ◽  
Vol 7 (4) ◽  
pp. 353-362 ◽  
Author(s):  
David Greenwood ◽  
Adrian Eley ◽  
Neil Pearson ◽  
Francis O'Grady
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):  
Francisco Javier Candel ◽  
Anne Santerre Henriksen ◽  
Christopher Longshaw ◽  
Yoshinori Yamano ◽  
Antonio Oliver

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S421-S422 ◽  
Author(s):  
Kenneth V I Rolston ◽  
Bahgat Gerges ◽  
Issam Raad ◽  
Samuel L Aitken ◽  
Ruth Reitzel ◽  
...  

Abstract Background Gram-negative bacilli (GNB) are now the predominant cause of bacterial infection in cancer patients (CP). Many GNB are problematic because they have become resistant to commonly used antibiotics. Cefiderocol (CFDC), a novel siderophore cephalosporin, is active against a wide spectrum of GNB. We evaluated its in vitro activity and that of eleven comparator agents against GNB isolated from CP. Methods A total of 341 recent GNB blood isolates from CP were tested using CLSI approved methods for MIC determination by broth microdilution. Comparator agents were amikacin (A), aztreonam (AZ), ceftazidime (CZ), ceftazidime/avibactam (CAV), cefepime (CEF), ciprofloxacin (CIP), colistin (CL), meropenem (MR), ceftolozane/tazobactam (C/T), tigecycline (TG), and trimethoprim/sulfamethoxazole (T/S). Results CFDC MIC90s as mg/L were: S. maltophilia [50 isolates] 0.25, E. coli (ESBL−) [50 isolates] 0.5, E. coli (ESBL+) [51 isolates] 2.0, K. pneumoniae (ESBL− and +) [60 isolates] 0.5; K. pneumoniae (CRE) [22 isolates] 2.0; P. aeruginosa (MDR) [32 isolates] 1.0; E. cloacae [27 isolates] 4.0; Achromobacter spp. [15 isolates] 0.12. CFDC inhibited P. agglomerans, Burkholderia spp., Sphingomonas spp., Ochrobactrum spp. at ≤1 mg/L [23 total isolates] and Elizabethkingia spp. and R. radiobacter at ≤8 mg/L [11 total isolates]. Among comparator agents, only T/S had consistent activity against S. maltophilia. For E. coli (ESBL− and +) MR, TG, CAV, CL were most active. For K. pneumoniae (ESBL–and +) MR, CAV were most active. For K. pneumoniae (CRE) and P. aeruginosa (MDR), none of the comparators had significant activity. For E. cloacae, MR, A, CAV, TG were most active. Among the uncommon organisms, MR and TG had the greatest activity. Conclusion Although susceptibility breakpoints have yet to be determined, CFDC has significant activity (≤4 mg/L) against most problematic Gram-negative organisms causing infections in CP based on available pharmacokinetic/pharmacodynamic data. In particular, its activity against S. maltophilia was superior to the comparators. Also, it was the most active agent against P. aeruginosa (MDR) and K. pneumoniae (CRE). Based on our results, CFDC warrants clinical evaluation for the treatment of blood stream infections caused by GNB in CP. Disclosures K. V. I. Rolston, Merck: Investigator, Research grant; JMI Laboratories: Investigator, Research grant; Shionogi (Japan): Investigator, Research grant. B. Gerges, Shionogi: Collaborator, Research support. S. L. Aitken, Shionogi: Scientific Advisor, Consulting fee; Merck: Scientific Advisor, Consulting fee; Medicines Co: Scientific Advisor, Consulting fee; Achaogen: Scientific Advisor, Consulting fee; Zavante: Scientific Advisor, Consulting fee; R. Prince, Shionogi: Investigator, Research support. Merck: Investigator, Research support.


Author(s):  
David W Wareham ◽  
M H F Abdul Momin ◽  
Lynette M Phee ◽  
Michael Hornsey ◽  
Joseph F Standing

Abstract Background β-Lactam (BL)/β-lactamase inhibitor (BLI) combinations are widely used for the treatment of Gram-negative infections. Cefepime has not been widely studied in combination with BLIs. Sulbactam, with dual BL/BLI activity, has been partnered with very few BLs. We investigated the potential of cefepime/sulbactam as an unorthodox BL/BLI combination against MDR Gram-negative bacteria. Methods In vitro activity of cefepime/sulbactam (1:1, 1:2 and 2:1) was assessed against 157 strains. Monte Carlo simulation was used to predict the PTA with a number of simulated cefepime combination regimens, modelled across putative cefepime/sulbactam breakpoints (≤16/≤0.25 mg/L). Results Cefepime/sulbactam was more active (MIC50/MIC90 8/8–64/128 mg/L) compared with either drug alone (MIC50/MIC90 128 to >256 mg/L). Activity was enhanced when sulbactam was added at 1:1 or 1:2 (P < 0.05). Reduction in MIC was most notable against Acinetobacter baumannii and Enterobacterales (MIC 8/8–32/64 mg/L). Pharmacokinetic/pharmacodynamic modelling highlighted that up to 48% of all isolates and 73% of carbapenem-resistant A. baumannii with a cefepime/sulbactam MIC of ≤16/≤8 mg/L may be treatable with a high-dose, fixed-ratio (1:1 or 1:2) combination of cefepime/sulbactam. Conclusions Cefepime/sulbactam (1:1 or 1:2) displays enhanced in vitro activity versus MDR Gram-negative pathogens. It could be a potential alternative to existing BL/BLI combinations for isolates with a cefepime/sulbactam MIC of 16/8 mg/L either as a definitive treatment or as a carbapenem-sparing option.


2006 ◽  
Vol 50 (6) ◽  
pp. 2261-2264 ◽  
Author(s):  
Hee-Soo Park ◽  
Hyun-Joo Kim ◽  
Min-Jung Seol ◽  
Dong-Rack Choi ◽  
Eung-Chil Choi ◽  
...  

ABSTRACT DW-224a showed the most potent in vitro activity among the quinolone compounds tested against clinical isolates of gram-positive bacteria. Against gram-negative bacteria, DW-224a was slightly less active than the other fluoroquinolones. The in vivo activities of DW-224a against gram-positive bacteria were more potent than those of other quinolones.


Sign in / Sign up

Export Citation Format

Share Document