scholarly journals 2383. In Vitro Activity of Ceftolozane–Tazobactam in Comparison With Ceftazidime–Avibactam vs. Antimicrobial Non-Susceptible Pseudomonas aeruginosa Clinical Isolates, Including Multidrug-Resistant and Extensively Drug-Resistant Subsets: CANWARD, 2007–2017

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S710-S710
Author(s):  
Andrew Walkty ◽  
Heather J Adam ◽  
Melanie Baxter ◽  
Philippe Lagace-Wiens ◽  
James Karlowsky ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Multidrug Resistant ◽  
Vitro Activity ◽  
Clinical Isolates ◽  
Drug Resistant ◽  
In Vitro Activity ◽  
Extensively Drug Resistant

scholarly journals In Vitro Activity of Ceftolozane-Tazobactam vs. Antimicrobial Non-Susceptible Pseudomonas aeruginosa Clinical Isolates Obtained from Across Canada as Part of the CANWARD Study, 2008–2016

2017 ◽  
Vol 4 (suppl_1) ◽  
pp. S372-S372
Author(s):  
Andrew Walkty ◽  
Heather J Adam ◽  
Melanie Baxter ◽  
Philippe Lagace-Wiens ◽  
James Karlowsky ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Multidrug Resistant ◽  
Vitro Activity ◽  
Clinical Isolates ◽  
In Vitro Activity ◽  
Research Support ◽  
Research Relationship ◽  
Inhibitor Combination ◽  
Patient Infection

Abstract Background Ceftolozane-tazobactam (C/T) is a novel β-lactam β-lactamase inhibitor combination with a broad spectrum of activity that includes Pseudomonas aeruginosa. The purpose of this study was to evaluate the in vitro activity of C/T and relevant comparators vs. a large collection of antimicrobial non-susceptible (NS) P. aeruginosa clinical isolates obtained from patients across Canada (CANWARD, 2008–2016). Methods From January 2008 to December 2016, inclusive, 12 to 15 sentinel hospitals across Canada submitted clinical isolates from patients attending ERs, medical and surgical wards, hospital clinics, and ICUs (CANWARD). Each center was asked to annually submit clinical isolates (consecutive, one per patient/infection site) from blood, respiratory, urine, and wound infections. Susceptibility testing was performed using broth microdilution as described by CLSI. Multidrug-resistant (MDR) P. aeruginosa were defined as isolates that tested NS to at least one antimicrobial from ≥3 classes. Extensively drug-resistant (XDR) P. aeruginosa were defined as isolates that tested NS to at least one antimicrobial from ≥5 classes. Results 3229 P. aeruginosa isolates were obtained as a part of CANWARD. The in vitro activity of C/T and relevant comparators is presented below. Conclusion C/T demonstrated excellent in vitro activity vs. antimicrobial NS P. aeruginosa clinical isolates, including MDR, XDR, and meropenem NS subsets. It may prove useful in the treatment of infections caused by these organisms. Disclosures D. Hoban, Abbott: Research relationship, Research support Achaogen: Research relationship, Research support Astellas: Research relationship, Research support Merck Canada: Research relationship, Research support Merck USA: Research relationship, Research support Paratek Pharma: Research relationship, Research support Pharmascience: Research relationship, Research support Sunovion: Research relationship, Research support Tetraphase: Research relationship, Research support The Medicines Co.: Research relationship, Research support Zoetis: Research relationship, Research support; G. Zhanel, Achaogen: Research relationship, Research support Astellas: Research relationship, Research support Merck Canada: Research relationship, Research support Merck USA: Research relationship, Research support Paratek Pharma: Research relationship, Research support Pharmascience: Research relationship, Research support Sunovion: Research relationship, Research support Tetraphase: Research relationship, Research support The Medicines Co.: Research relationship, Research support Zoetis: Research relationship, Research support

scholarly journals 1581. Comparative In Vitro Activity of Ceftolozane/tazobactam and Comparator Agents Against Enterobacteriaceae and Pseudomonas Aeruginosa Clinical Isolates in Colombia

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S577-S577
Author(s):  
Cristhian Hernández-Gómez ◽  
Elsa De La Cadena ◽  
Maria F Mojica ◽  
Adriana Correa ◽  
Marcela Perengüez ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Vitro Activity ◽  
Clinical Isolates ◽  
In Vitro Activity ◽  
Healthcare Associated ◽  
Resistance Rates ◽  
Outer Membrane Permeability

Abstract Background Multidrug-resistant Enterobacteriaceae (Ent) and Pseudomonas aeruginosa (Pae) are involved in a considerable number of healthcare-associated infections, thus representing a therapeutic challenge. Ceftolozane–tazobactam (C/T) is a combination of a novel cephalosporin with a known β-lactamase inhibitor. Ceftolozane has high affinity for penicillin-binding proteins, improved outer membrane permeability, increased stability against efflux and enhanced stability against chromosomal AmpC β-lactamases compared with other β-lactam antibiotics. This agent is not active against carbapenemases. We evaluated the in vitro activity of C/T against clinical isolates of Ent and Pae collected from 2016- 2017 and compared it to the activity of broad-spectrum antimicrobial agents. Methods 1.644 Ent and Pae non-duplicate clinical isolates were collected in 13 medical centers located in 12 Colombian cities. Minimum inhibitory concentrations (MIC) were performed by broth microdilution and interpreted according to current CLSI guidelines. Isolates tested included 813 Escherichia coli (Eco), 441 Klebsiella pneumoniae (Kpn), 82 Enterobacter spp., (Enb); 60 Serratia marcescens (Sma) and 248 Pae. Comparator agents were ceftriaxone (CRO), cefotaxime (CTX), ceftazidime (CAZ), cefepime (FEP), piperacillin/tazobactam (TZP), ertapenem (ETP), imipenem (IMI), meropenem (MEM). Results Susceptibilities to C/T and comparators of 4 Ent species and Pae are shown in Table 1. Compared with other β-lactams such as CRO, CAZ, TZP, and FEP, C/T had considerably higher susceptibility rates against ESBL, non-carbapenem-resistant (CR) Eco and Kpn isolates. C/T MIC50/90 were: Eco (≤1/≤1); Kpn (≤1/128); Enb (≤1/64); Sma (≤1/≥256); Pae (≤1/≥256). In the case of P.aeruginosa despite the high resistance rates observed in the study, C/T had the best susceptibility, even higher than the carbapenems. Conclusion Overall, C/T demonstrated higher in vitro activity than currently available cephalosporins and TZP when tested against Ent and Pae. C/T provides an important treatment option against infections caused by non-carbapenemase producing Gram-negative pathogens. Further studies are warranted to identify an emerging mechanism of resistance in Colombia. Disclosures All authors: No reported disclosures.

scholarly journals 1594. Ceftolozane–Tazobactam Demonstrates Higher In Vitro Susceptibility than Ceftazidime–Avibactam Against Pseudomonas aeruginosa Isolated from Respiratory Tract of Adult Cystic Fibrosis Patients

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S581-S582
Author(s):  
Patrick James Nolan ◽  
Tiffeny Smith ◽  
James D Finklea ◽  
Leah Cohen ◽  
Raksha Jain
Keyword(s):  
Cystic Fibrosis ◽  
Pseudomonas Aeruginosa ◽  
Susceptibility Testing ◽  
Clinical Laboratory ◽  
Multidrug Resistant ◽  
Vitro Activity ◽  
Drug Resistant ◽  
In Vitro Activity ◽  
In Vitro Susceptibility

Abstract Background Pseudomonas aeruginosa is a commonly isolated pathogen in adults with cystic fibrosis (CF). Antimicrobial resistance is an escalating problem due to chronic colonization and frequent antimicrobial exposure. Ceftolozane–tazobactam (C/T) and ceftazidime–avibactam (CZA) exhibit promising activity against antimicrobial-resistant organisms, including P. aeruginosa. In this study, we compared in vitro activity of C/T and CZA against P. aeruginosa isolated from respiratory cultures obtained from adult patients with CF. Methods This is a retrospective study of respiratory cultures positive for P. aeruginosa collected from adult CF patients between January 1, 2015 to November 30, 2018. The first isolate per patient per year that underwent susceptibility testing for C/T, CZA, and colistin were included in the study. All isolates underwent in-house susceptibility testing for 9 anti-pseudomonal agents according to the methodology established by the Clinical Laboratory Standards Institute (CLSI). Susceptibility testing of C/T, CZA, and colistin were performed by a reference lab. Isolates were classified into 3 drug-resistant categories using the following definition: multidrug-resistant (MDR) non-susceptible (NS) to ≥1 agent in ≥3 different antimicrobial classes, extensive drug-resistant (XDR) NS to 4 or 5 different classes, and pan drug-resistant (PDR) NS to all 6 classes except colistin. Results Forty-two P. aeruginosa respiratory isolates from 32 patients with CF were included. The overall susceptibility to C/T and CZA was 59.5% and 42.9%, respectively. Thirty-eight (90%) isolates were considered MDR with susceptibility of 55.3% to C/T and 44.7% to CZA. Among the 11 XDR isolates, susceptibility to C/T was 81.8% vs. CZA 72.7%. Susceptibility to C/T vs. CZA was also higher (37.5% vs. 25%) among the 24 PDR isolates. Conclusion Among P. aeruginosa isolated from CF respiratory cultures, C/T appears to have better in vitro activity compared with CZA, and remained true among isolates considered XDR and PDR. These results suggest using C/T while awaiting susceptibilities when standard anti-pseudomonal agents cannot be used. Future studies evaluating clinical outcomes for the treatment of pulmonary CF exacerbations are needed to assess the applicability of in vitro susceptibility data. Disclosures All authors: No reported disclosures.

scholarly journals In Vitro Activity of Ceftazidime Combined with NXL104 versus Pseudomonas aeruginosa Isolates Obtained from Patients in Canadian Hospitals (CANWARD 2009 Study)

2011 ◽  
Vol 55 (6) ◽  
pp. 2992-2994 ◽  
Author(s):  
A. Walkty ◽  
M. DeCorby ◽  
P. R. S. Lagacé-Wiens ◽  
J. A. Karlowsky ◽  
D. J. Hoban ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Multidrug Resistant ◽  
Vitro Activity ◽  
Clinical Isolates ◽  
In Vitro Activity ◽  
Broth Microdilution ◽  
Content Type ◽  
Presence And Absence

ABSTRACTThein vitroactivity of ceftazidime in combination with NXL104 versus 470Pseudomonas aeruginosaclinical isolates was evaluated using Clinical and Laboratory Standards Institute (CLSI) broth microdilution methods. Ceftazidime had MIC90s of 8 μg/ml and 32 μg/ml in the presence and absence of NXL104, respectively. Of 25 multidrug-resistantP. aeruginosaisolates, the percentages with a ceftazidime MIC of ≤8 μg/ml with and without NXL104 were 60% and 4%, respectively. These data suggest that the ceftazidime-NXL104 combination may prove useful for treating manyP. aeruginosainfections.

scholarly journals 1280. In-Vitro Activity of Cefiderocol, Imipenem/Relebactam, & Ceftazidime/Avibactam in Ceftolozane/Tazobactam Resistant Strains of Multidrug Resistant Pseudomonas aeruginosa

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S655-S655
Author(s):  
Daniel Navas ◽  
Angela Charles ◽  
Amy Carr ◽  
Jose Alexander
Keyword(s):  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Vitro Activity ◽  
Clinical Isolates ◽  
Resistance Testing ◽  
Clinical Samples ◽  
In Vitro Activity ◽  
Carbapenemase Gene ◽  
Resistant Strains

Abstract Background The activity of imipenem/relebactam (I/R), ceftazidime/avibactam (CZA) and cefiderocol (FDC) were evaluated against clinical isolates of multidrug resistant (MDR) strains of P. aeruginosa which was resistant to ceftolozane/tazobactam (C/T). The recent increase of MDR P. aeruginosa strains isolated from clinical samples has prompted research and development of new antimicrobials that can withstand its multiple resistance mechanisms. C/T is an effective option for treatment of MDR P. aeruginosa in our facility with only 10% of resistance in MDR strains, but the emergence of resistance may occur due to the presence of a carbapenemase gene or an ampC mutation. Methods Antimicrobial susceptibility testing for C/T Etest® (bioMérieux, Inc.) were performed on all MDR strains initially screened by the VITEK2® (bioMérieux, Inc.). 10% (n=20) of all MDR isolates were resistant to C/T by the CLSI 2019 breakpoints. These resistant isolates were tested for presence of a carbapenemase gene using the GeneXpert CARBA-R (Cepheid®) PCR and against CZA Etest® (bioMérieux, Inc.) I/R gradient strips (Liofilchem®) and FDC broth microdilution (Thermo Scientific™ Sensititre™). Results A total of 20 clinical isolates of MDR P. aeruginosa resistant to C/T were tested following standardized CLSI protocols and techniques. All 20 isolates were screened for the presence of a carbapenemase gene (blaVIM, blaNDM, blaKPC, blaOXA-48, blaIMP). A blaVIM gene was detected in 6 (30%) out of 20 isolates. FDC demonstrated the greatest activity with 85% (n=17) of susceptible isolates (CLSI MIC <4µg/dL). CZA (CLSI MIC <8µg/dL) and I/R (FDA MIC <2µg/dL) showed 15% (n=3) and 10% (n=2) of susceptible isolates respectively. FDC was active against all 6 blaVIM isolates, where all 6 strains were resistant to CZA and I/R as expected. 3 isolates tested non-susceptible against FDC; additional characterization was not performed at this time. Conclusion Based on these results, FDC demonstrated the greatest in-vitro activity against C/T resistant strains of MDR P. aeruginosa. FDC also demonstrated activity against all 6 MDR P. aeruginosa carrying blaVIM gene. FDC is a strong option to consider on MDR P. aeruginosa strains based on a resistance testing algorithm and a cost/effective protocol. Disclosures All Authors: No reported disclosures

Sign in / Sign up

Export Citation Format

Share Document