Activity of ceftolozane-tazobactam and comparators against Pseudomonas aeruginosa from patients in different risk strata - SMART United States 2016-2017

Activity of ceftolozane/tazobactam, imipenem/relebactam and ceftazidime/avibactam against clinical Gram-negative isolates-SMART United States 2019-21

Background

Ongoing national and international surveillance efforts are critical components of antimicrobial stewardship, resistance monitoring, and drug development programs. In this report, we summarize the results of ceftolozane/tazobactam, imipenem/relebactam, ceftazidime/avibactam and comparator agent testing against 10 509 Enterobacterales and 2524 Pseudomonas aeruginosa collected by USA clinical laboratories in 2019-21 as part of the SMART global surveillance programme.

Methods

MICs were determined by CLSI broth microdilution and interpreted using 2023 CLSI M100 breakpoints.

Results

Most Enterobacterales were ceftazidime/avibactam susceptible (>99%), meropenem susceptible (99%) and ceftolozane/tazobactam susceptible (94%). Non-Morganellaceae Enterobacterales were also highly susceptible to imipenem/relebactam (99%). Ceftolozane/tazobactam inhibited 94% of Escherichia coli and 89% of Klebsiella pneumoniae with ceftriaxone non-susceptible/non-carbapenem-resistant phenotypes. Against P. aeruginosa, ceftolozane/tazobactam (97% susceptible) was more active than ceftazidime/avibactam (95%) and imipenem/relebactam (91%). MDR and difficult-to-treat resistance (DTR) phenotypes were identified in 13% and 7% of P. aeruginosa isolates, respectively. Ceftolozane/tazobactam remained active against 78% of MDR P. aeruginosa (13% and 23% higher than ceftazidime/avibactam and imipenem/relebactam, respectively) and against 74% of DTR P. aeruginosa (24% and 37% higher than ceftazidime/avibactam and imipenem/relebactam, respectively). Length of hospital stay at the time of specimen collection, ward type and infection type resulted in percent susceptible value differences of >5% across isolate demographic strata for some antimicrobial agent/pathogen combinations.

Conclusions

We conclude that in the USA, in 2019-21, carbapenem (meropenem) resistance remained uncommon in Enterobacterales and ceftolozane/tazobactam was more active than both ceftazidime/avibactam and imipenem/relebactam against P. aeruginosa.

Safety and Efficacy of Ceftolozane/Tazobactam Versus Meropenem in Neonates and Children With Complicated Urinary Tract Infection, Including Pyelonephritis: A Phase 2, Randomized Clinical Trial

BACKGROUND

Ceftolozane/tazobactam, a cephalosporin-β-lactamase inhibitor combination, active against multidrug-resistant Gram-negative pathogens, is approved for treatment of adults with complicated urinary tract infections (cUTI). Safety and efficacy of ceftolozane/tazobactam in pediatric participants with cUTI, including pyelonephritis, were assessed.

METHODS

This phase 2 study (NCT03230838) compared ceftolozane/tazobactam with meropenem for treatment of cUTI in participants from birth to <18 years of age. The primary objective was safety and tolerability. Key secondary end points included clinical cure and per-participant microbiologic response rates at end of treatment (EOT) and test of cure (TOC) visits.

RESULTS

The microbiologic modified intent-to-treat (mMITT) population included 95 participants (ceftolozane/tazobactam, n = 71; meropenem, n = 24). The most common diagnosis and pathogen were pyelonephritis (ceftolozane/tazobactam, 84.5%; meropenem, 79.2%) and Escherichia coli (ceftolozane/tazobactam, 74.6%; meropenem, 87.5%); 5.7% (ceftolozane/tazobactam) and 4.8% (meropenem) of E. coli isolates were extended-spectrum β-lactamase-producers. Rates of adverse events were similar between treatment groups (any: ceftolozane/tazobactam, 59.0% vs. meropenem, 60.6%; drug-related: ceftolozane/tazobactam, 14.0% vs. meropenem, 15.2%; serious: ceftolozane/tazobactam, 3.0% vs. meropenem, 6.1%). Rates of clinical cure for ceftolozane/tazobactam and meropenem at EOT were 94.4% and 100% and at TOC were 88.7% and 95.8%, respectively. Rates of microbiologic eradication for ceftolozane/tazobactam and meropenem at EOT were 93.0% and 95.8%, and at TOC were 84.5% and 87.5%, respectively.

CONCLUSIONS

Ceftolozane/tazobactam had a favorable safety profile in pediatric participants with cUTI; rates of clinical cure and microbiologic eradication were high and similar to meropenem. Ceftolozane/tazobactam is a safe and effective new treatment option for children with cUTI, especially due to antibacterial-resistant Gram-negative pathogens.

In Vitro Activity of Ceftolozane-Tazobactam, Imipenem-Relebactam, Ceftazidime-Avibactam, and Comparators against Pseudomonas aeruginosa Isolates Collected in United States Hospitals According to Results from the SMART Surveillance Program, 2018 to 2020

Ceftolozane-tazobactam (C/T), imipenem-relebactam (IMR), and ceftazidime-avibactam (CZA) were tested against 2,531 P. aeruginosa strains isolated from patients in the United States from 2018 to 2020 as part of the SMART (Study for Monitoring Antimicrobial Resistance Trends) surveillance program. MICs were determined by CLSI broth microdilution and interpreted using CLSI M100 (2021) breakpoints. Imipenem-, IMR-, or C/T-nonsusceptible isolates were screened for β-lactamase genes: 96.4% of all isolates and ≥70% of multidrug-resistant (MDR), pan-β-lactam-nonsusceptible, and difficult-to-treat resistance (DTR) isolates were C/T-susceptible; 52.2% of C/T-nonsusceptible isolates remained susceptible to IMR compared to 38.9% for CZA; and 1.7% of isolates tested were nonsusceptible to both C/T and IMR versus 2.2% of isolates with a C/T-nonsusceptible and CZA-resistant phenotype (a difference of 12 isolates). C/T and IMR modal MICs for pan-β-lactam-nonsusceptible isolates remained at or below their respective susceptible MIC breakpoints from 2018 to 2020, while the modal MIC for CZA increased 2-fold from 2018 to 2019 and exceeded the CZA-susceptible MIC breakpoint in both 2019 and 2020. Only six of 802 molecularly characterized isolates carried a metallo-β-lactamase, and two isolates carried a GES carbapenemase. Most P. aeruginosa isolates were C/T-susceptible, including many with MDR, pan-β-lactam-nonsusceptible, DTR, CZA-resistant, and IMR-nonsusceptible phenotypes. While C/T was the most active antipseudomonal agent, IMR demonstrated greater activity than CZA against isolates nonsusceptible to C/T.

New Antibiotics for Hospital-Acquired Pneumonia and Ventilator-Associated Pneumonia

Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) represent one of the most common hospital-acquired infections, carrying a significant morbidity and risk of mortality. Increasing antibiotic resistance among the common bacterial pathogens associated with HAP and VAP, especially Enterobacterales and nonfermenting gram-negative bacteria, has made the choice of empiric treatment of these infections increasingly challenging. Moreover, failure of initial empiric therapy to cover the causative agents associated with HAP and VAP has been associated with worse clinical outcomes. This review provides an overview of antibiotics newly approved or in development for the treatment of HAP and VAP. The approved antibiotics include ceftobiprole, ceftolozane-tazobactam, ceftazidime-avibactam, meropenem-vaborbactam, imipenem-relebactam, and cefiderocol. Their major advantages include their high activity against multidrug-resistant gram-negative pathogens.

In Vitro Activity of Ceftolozane/Tazobactam against Gram-Negative Isolates collected from ICU Patients with Lower Respiratory Tract Infections in Seven Asian Countries - SMART 2017-2019

OBJECTIVES

Antimicrobial resistance is one of the top 10 global public health threats. Especially high rates of resistance have been reported for isolates from ICU patients, requiring expanded treatment options in this setting. We evaluated the activity of ceftolozane/tazobactam and comparators against gram-negative isolates collected from patients with lower respiratory tract infections (LRTI) in ICUs in seven Asian countries.

METHODS

In 2017-2019, up to 100 consecutive aerobic gram-negative LRTI isolates were collected per year at each of 37 hospitals. MICs were determined using the Clinical and Laboratory Standards Institute reference broth microdilution method.

RESULTS

Overall, ceftolozane/tazobactam was active against 72% of 1408 Enterobacterales and 86% of 761 P. aeruginosa isolates. Susceptibility to the non-carbapenem β-lactam comparators, including piperacillin/tazobactam, was 52-67% among Enterobacterales isolates, and the activity of all β-lactam comparators, including meropenem, was 57-70% among P. aeruginosa. Ceftolozane/tazobactam maintained activity against 61% of meropenem-nonsusceptible and 64% of piperacillin/tazobactam-nonsusceptible P. aeruginosa isolates. At the country-level, ceftolozane/tazobactam activity ranged from >90% against Enterobacterales isolates from Hong Kong and South Korea to <64% in Thailand and Vietnam, and from >90% against P. aeruginosa from South Korea, Malaysia, Philippines, and Taiwan to <75% in Thailand and Vietnam. Correspondingly, the proportions of carbapenemase-positive isolates among Enterobacterales and P. aeruginosa isolates were highest in Thailand and Vietnam.

CONCLUSIONS

Ceftolozane/tazobactam provides a potential treatment option for ICU patients in Asia, which is especially important considering the reduced activity of commonly used β-lactams against the studied ICU isolates. Knowledge of local resistance patterns should inform empiric therapy decision-making.

Discovery of a Series of Theophylline Derivatives Containing 1,2,3-Triazole for Treatment of Non-Small Cell Lung Cancer

Chemotherapy is the most common clinical treatment for non-small cell lung cancer (NSCLC), but low efficiency and high toxicity of current chemotherapy drugs limit their clinical application. Therefore, it is urgent to develop hypotoxic and efficient chemotherapy drugs. Theophylline, a natural compound, is safe and easy to get, and it can be used as a modified scaffold structure and hold huge potential for developing safe and efficient antitumor drugs. Herein, we linked theophylline with different azide compounds to synthesize a new type of 1,2,3-triazole ring-containing theophylline derivatives. We found that some theophylline1,2,3-triazole compounds showed a good tumor-suppressive efficacy. Especially, derivative d17 showed strong antiproliferative activity against a variety of cancer cells in vitro, including H460, A549, A2780, LOVO, MB-231, MCF-7, OVCAR3, SW480, and PC-9. It is worth noting that the two NSCLC cell lines H460 H and A549 are sensitive to compound d17 particularly, with IC50 of 5.929 ± 0.97 μM and 6.76 ± 0.25 μM, respectively. Compound d17 can significantly induce cell apoptosis by increasing the ratio of apoptotic protein Bax/Bcl-2 by downregulating the expression of phosphorylated Akt protein, and it has little toxicity to normal hepatocyte cells LO2 at therapeutic concentrations. These data indicate that these theophylline acetic acid-1,2,3-triazole derivatives may be potential drug candidates for anti-NSCLC and are worthy of further study.

Ceftolozane/Tazobactam and Imipenem/Relebactam Cross-Susceptibility Among Clinical Isolates of Pseudomonas aeruginosa From Patients With Respiratory Tract Infections in ICU and Non-ICU Wards-SMART United States 2017-2019

BACKGROUND

Carbapenem-nonsusceptible and multidrug-resistant (MDR) P. aeruginosa, which are more common in patients with lower respiratory tract infections (LRTIs) and in patients in intensive care units (ICUs), pose difficult treatment challenges and may require new therapeutic options. Two β-lactam/β-lactamase inhibitor combinations, ceftolozane/tazobactam (C/T) and imipenem/relebactam (IMI/REL), are approved for treatment of hospital-acquired/ventilator-associated bacterial pneumonia.

METHODS

The Clinical and Laboratory Standards Institute-defined broth microdilution methodology was used to determine minimum inhibitory concentrations (MICs) against P. aeruginosa isolates collected from patients with LRTIs in ICUs (n = 720) and non-ICU wards (n = 914) at 26 US hospitals in 2017-2019 as part of the Study for Monitoring Antimicrobial Resistance Trends (SMART) surveillance program.

RESULTS

Susceptibility to commonly used β-lactams including carbapenems was 5-9 percentage points lower and MDR rates 7 percentage points higher among isolates from patients in ICUs than those in non-ICU wards (P < .05). C/T and IMI/REL maintained activity against 94.0% and 90.8% of ICU isolates, respectively, while susceptibility to all comparators except amikacin (96.0%) was 63%-76%. C/T and IMI/REL inhibited 83.1% and 68.1% of meropenem-nonsusceptible (n = 207) and 71.4% and 65.7% of MDR ICU isolates (n = 140), respectively. Among all ICU isolates, only 2.5% were nonsusceptible to both C/T and IMI/REL, while 6.7% were susceptible to C/T but not to IMI/REL and 3.5% were susceptible to IMI/REL but not to C/T.

CONCLUSIONS

These data suggest that susceptibility to both C/T and IMI/REL should be considered for testing at hospitals, as both agents could provide important new options for treating patients with LRTIs, especially in ICUs where collected isolates show substantially reduced susceptibility to commonly used β-lactams.

Antimicrobial activity of ceftolozane-tazobactam against Enterobacterales and Pseudomonas aeruginosa recovered during the Study for Monitoring Antimicrobial Resistance Trends (SMART) program in Spain (2016-2018)

OBJECTIVE

To analyse the susceptibility to ceftolozane-tazobactam and comparators in Enterobacterales and Pseudomonas aeruginosa isolates recovered from intraabdominal (IAI), urinary (UTI), respiratory (RTI) and bloodstream infection (BSI) in the SMART (Study for Monitoring Antimicrobial Resistance Trends) study.

METHODS

The susceptibility of 5,351 isolates collected in 11 Spanish hospitals (2016-2018) were analysed (EUCAST-2020 criteria) by broth microdilution and were phenotypically studied for the presence of extended-spectrum beta-lactamases (ESBL). Ceftolozane-tazobactam and/or carbapenem resistant isolates were genetically characterized for ESBL and carbapenemases.

RESULTS

Escherichia coli was the most frequent pathogen (49.3% IAI, 54.9% UTI, 16.7% RTI and 50% BSI), followed by Klebsiella pneumoniae (11.9%, 19.1%, 13.1% and 15.4%, respectively). P. aeruginosa was isolated in 9.3%, 5.6%, 32% and 9%, respectively. The frequency of isolates with ESBLs (2016-2017) was: 30.5% K. pneumoniae, 8.6% E. coli, 2.3% Klebsiella oxytoca and 0.7% Proteus mirabilis. Ceftolozane-tazobactam was very active against non-ESBL-(99.3% susceptible) and ESBL-(95.2%) producing E. coli being less active against K. pneumoniae (98% and 43.1%, respectively) isolates. CTX-M-15 was the most prevalent ESBL in E. coli (27.5%) and K. pneumoniae (51.9%) frequently associated with OXA-48-like carbapenemase. Overall, 93% of P. aeruginosa isolates were susceptible to ceftolozane-tazobactam, preserving this activity (>75%) in isolates resistant to other beta-lactams except in those resistant to meropenen or ceftazidime-avibactam. GES-5, PER-1, VIM-1/2 were the most prevalent enzymes in isolates resistant to ceftolozane-tazobactam.

CONCLUSIONS

Ceftolozane-tazobactam showed high activity rates against isolates recovered in the SMART study although it was affected in K. pneumoniae and P. aeruginosa isolates with ESBL and/or carbapenemases.

Ceftolozane/Tazobactam for Resistant Drugs Pseudomonas aeruginosa Respiratory Infections: A Systematic Literature Review of the Real-World Evidence

Background: Ceftolozane/tazobactam (C/T) is a β-lactam/β-lactamase inhibitor combination that mainly targets Gram-negative bacteria. The current international guidelines recommend including C/T treatment in the empirical therapy for hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP). Pseudomonas aeruginosa (PA) is one of the most challenging Gram-negative bacteria. We conducted a systematic review of all cases reported in the literature to summarize the existing evidence. Methods: The main electronic databases were screened to identify case reports of patients with drug-resistant PA respiratory infections treated with C/T. Results: A total of 22 publications were included for a total of 84 infective episodes. The clinical success rate was 72.6% across a wide range of comorbidities. The 45.8% of patients treated with C/T presented colonization by PA. C/T was well tolerated. Only six patients presented adverse events, but none had to stop treatment. The most common therapeutic regimens were 1.5 g every 8 h and 3 g every 8 h. Conclusion: C/T may be a valid therapeutic option to treat multidrug-resistant (MDR), extensively drug-resistant (XDR), pandrug-resistant (PDR), and carbapenem-resistant (CR) PA infections. However, further data are necessary to define the optimal treatment dosage and duration.

Nosocomial Pneumonia in the Era of Multidrug-Resistance: Updates in Diagnosis and Management

Nosocomial pneumonia (NP), including hospital-acquired pneumonia in non-intubated patients and ventilator-associated pneumonia, is one of the most frequent hospital-acquired infections, especially in the intensive care unit. NP has a significant impact on morbidity, mortality and health care costs, especially when the implicated pathogens are multidrug-resistant ones. This narrative review aims to critically review what is new in the field of NP, specifically, diagnosis and antibiotic treatment. Regarding novel imaging modalities, the current role of lung ultrasound and low radiation computed tomography are discussed, while regarding etiological diagnosis, recent developments in rapid microbiological confirmation, such as syndromic rapid multiplex Polymerase Chain Reaction panels are presented and compared with conventional cultures. Additionally, the volatile compounds/electronic nose, a promising diagnostic tool for the future is briefly presented. With respect to NP management, antibiotics approved for the indication of NP during the last decade are discussed, namely, ceftobiprole medocaril, telavancin, ceftolozane/tazobactam, ceftazidime/avibactam, and meropenem/vaborbactam.