Activity of Ceftolozane/Tazobactam Against Gram-Negative Rods of the Family Enterobacteriaceae and Pseudomonas Spp. Isolated from Onco-Hematological Patients Hospitalized in a Clinical Hospital in Poland

Satisfactory In Vitro Activity of Ceftolozane–Tazobactam against Carbapenem-Resistant Pseudomonas aeruginosa But Not against Klebsiella pneumoniae Isolates

Background: Gram-negative rods are one of the most commonly isolated bacteria within human infections. These microorganisms are typically opportunistic pathogens that pose a serious threat to public health due to the possibility of transmission in the human population. Resistance to carbapenems is one of the most important antimicrobial resistance mechanisms amongst them. The aim of this study was to evaluate ceftolozane–tazobactam in vitro activity against carbapenem-resistant Pseudomonas aeruginosa and Klebsiella pneumoniae clinical strains. Information on the antimicrobial activity of this antimicrobial against Gram-negative rods was also supplemented with a brief review of the relevant literature. Methods: The research involved 316 strains of Gram-negative rods: P. aeruginosa—206 and K. pneumoniae—110. Results: Of the tested strains, 86.0% P. aeruginosa and 30.0% K. pneumoniae remained susceptible to ceftolozane–tazobactam. Conclusions: Therefore, ceftolozane–tazobactam might be a good option in the treatment of infections caused by carbapenem-resistant P. aeruginosa strains, including those in ICU patients. Meanwhile, due to dissemination of ESBLs among K. pneumoniae strains, infections with this etiology should not be treated with the ceftolozane–tazobactam combination.

Global evaluation of the antibacterial activity of Ceftolozane/Tazobactam against ESBLs-producing Escherichia coli and Klebsiella pneumoniae: a systematic review and meta-analysis

Background

Ceftolozane/Tazobactam is a β-lactam/β-lactamase inhibitor combination with a high range of efficacy and broad-spectrum action against multidrug-resistant bacterial strains.

Objectives

The present study aimed to analyze the in vitro activity of Ceftolozane/Tazobactam against extended-spectrum β-lactamases (ESBLs)-producing Escherichia coli (ESBLs-EC) and Klebsiella pneumonia (ESBLs-KP) in the published literature to provide international data on the antimicrobial stewardship programs.

Design

Systematic review and meta-analysis.

Methods

A systematic literature search was conducted on the Web of Science, Embase, PubMed, Scopus, and Google Scholar electronic databases from the beginning of databases to December 2022 to cover all published articles relevant to our scope.

Results

At last, 31 publications that met our inclusion criteria were selected for data extraction and analysis by Comprehensive Meta-Analysis Software. The pooled prevalence of Ceftolozane/Tazobactam susceptibility for ESBLs-EC and ESBLs-KP was estimated at 91.3% [95% confidence interval (CI): 90.1-92.5%] and 65.6% (95% CI: 60.8-70.2%), respectively. There was significant heterogeneity among the 31 studies for ESBLs-EC (χ2 = 91.621; p < 0.001; I2 = 67.256%) and ESBLs-KP (χ2 = 348.72; p < 0.001; I2 = 91.4%). Most clinical isolates of ESBLs-EC had MIC50 and MIC90 at a concentration of 0.5 and 2 µg/mL [minimum inhibitory concentration (MIC) at which 50% and 90% of isolates were inhibited], respectively. In contrast, most clinical isolates of ESBLs-KP had MIC50 and MIC90 at a concentration of 1 and 32 µg/mL, respectively.

Conclusion

Based on the meta-analysis results, Ceftolozane/Tazobactam has a more promising in vitro antibacterial activity against ESBLs-EC isolates from different clinical sources than ESBLs-KP isolates. Therefore, Ceftolozane/Tazobactam can be a useful therapeutic drug as an alternative to carbapenems. Randomized clinical trials are needed to provide clinical evidence to support these observations.

Pseudomonas aeruginosa Infections in Cancer Patients

Pseudomonas aeruginosa (P. aeruginosa) is one of the most frequent opportunistic microorganisms causing infections in oncological patients, especially those with neutropenia. Through its ability to adapt to difficult environmental conditions and high intrinsic resistance to antibiotics, it successfully adapts and survives in the hospital environment, causing sporadic infections and outbreaks. It produces a variety of virulence factors that damage host cells, evade host immune responses, and permit colonization and infections of hospitalized patients, who usually develop blood stream, respiratory, urinary tract and skin infections. The wide intrinsic and the increasing acquired resistance of P. aeruginosa to antibiotics make the treatment of infections caused by this microorganism a growing challenge. Although novel antibiotics expand the arsenal of antipseudomonal drugs, they do not show activity against all strains, e.g., MBL (metalo-β-lactamase) producers. Moreover, resistance to novel antibiotics has already emerged. Consequently, preventive methods such as limiting the transmission of resistant strains, active surveillance screening for MDR (multidrug-resistant) strains colonization, microbiological diagnostics, antimicrobial stewardship and antibiotic prophylaxis are of particular importance in cancer patients. Unfortunately, surveillance screening in the case of P. aeruginosa is not highly effective, and a fluoroquinolone prophylaxis in the era of increasing resistance to antibiotics is controversial.

Present and Future Perspectives on Therapeutic Options for Carbapenemase-Producing Enterobacterales Infections

Carbapenem-resistant Enterobacterales (CRE) are included in the list of the most threatening antibiotic resistance microorganisms, being responsible for often insurmountable therapeutic issues, especially in hospitalized patients and immunocompromised individuals and patients in intensive care units. The enzymatic resistance to carbapenems is encoded by different β-lactamases belonging to A, B or D Ambler class. Besides compromising the activity of last-resort antibiotics, CRE have spread from the clinical to the environmental sectors, in all geographic regions. The purpose of this review is to present present and future perspectives on CRE-associated infections treatment.

Evaluation of in vitro activity of ceftolozane-tazobactam in combination with other classes of antibacterial agents against Enterobacterales and Pseudomonas aeruginosa-the EM200 study

Ceftolozane-tazobactam is a cephalosporin/β-lactamase inhibitor combination developed for use against some β-lactam- and multidrug-resistant Gram-negative organisms. This study aimed to evaluate the in vitro activity of ceftolozane-tazobactam against clinical bacterial isolates at the University Hospital of Marrakech. This is a descriptive and analytical prospective study. A total of 143 Enterobacterales and 48 Pseudomonas aeruginosa isolates were collected from January 2018 to December 2018 from patients with respiratory, urinary and intra-abdominal infections. The identification was made by Phoenix automated system (BioMérieux). MIC50/90 were tested by broth microdilution for ceftolozane-tazobactam, and other drugs using dried panels. Antimicrobial susceptibility results were interpreted according to CLSI guidelines. Ceftolozane-tazobactam inhibited 98% of Escherichia coli (MIC_50/90; 0.25/0.5 μg/mL). The susceptibility rate of Klebsiella pneumoniae to ceftolozane-tazobactam was 68.8% (MIC_50/90, 0.5/>32 μg/mL); other Enterobacterales have shown susceptibility rates of 80.4% (MIC_50/90; 0.5/8 μg/mL). In carbapenemase-producing K. pneumoniae, the bla _OXA-48 mutation was found in two isolates. Susceptibility of P. aeruginosa to ceftolozane-tazobactam was 91.7% (MIC_50/90, 0.5/>32 μg/mL). In non-carbapenemase-producing P. aeruginosa, AmpC mutations were found in all isolates. Ceftolozane-tazobactam was satisfactorily active against a wide range of tested isolates and offers clinicians a potential therapeutic option even against resistant strains in patients with intra-abdominal infections, urinary tract infections and nosocomial pneumonia.

A rare emergence of resistance to ceftolozane/tazobactam in Klebsiella pneumoniae causing urinary tract infection

The management of infections caused by carbapenem-resistant organisms has been a challenge. We report a rare emergence of resistance to the novel beta-lactam/ beta-lactamase combination ceftolozane/tazobactam by Klebsiella pneumoniae, causing urinary tract infection. The K. pneumoniae, in this case, was reported to be sensitive to the other novel beta-lactam/ beta-lactamase combination of ceftazidime/avibactam. The timely administration of ceftazidime/avibactam resulted in prompt clinical resolution of the urinary tract infection caused by an extensively drug-resistant K. pneumoniae.

New β-Lactam-β-Lactamase Inhibitor Combinations

The limited armamentarium against drug-resistant Gram-negative bacilli has led to the development of several novel β-lactam-β-lactamase inhibitor combinations (BLBLIs). In this review, we summarize their spectrum of in vitro activities, mechanisms of resistance, and pharmacokinetic-pharmacodynamic (PK-PD) characteristics. A summary of available clinical data is provided per drug. Four approved BLBLIs are discussed in detail. All are options for treating multidrug-resistant (MDR) Enterobacterales and Pseudomonas aeruginosa Ceftazidime-avibactam is a potential drug for treating Enterobacterales producing extended-spectrum β-lactamase (ESBL), Klebsiella pneumoniae carbapenemase (KPC), AmpC, and some class D β-lactamases (OXA-48) in addition to carbapenem-resistant Pseudomonas aeruginosa Ceftolozane-tazobactam is a treatment option mainly for carbapenem-resistant P. aeruginosa (non-carbapenemase producing), with some activity against ESBL-producing Enterobacterales Meropenem-vaborbactam has emerged as treatment option for Enterobacterales producing ESBL, KPC, or AmpC, with similar activity as meropenem against P. aeruginosa Imipenem-relebactam has documented activity against Enterobacterales producing ESBL, KPC, and AmpC, with the combination having some additional activity against P. aeruginosa relative to imipenem. None of these drugs present in vitro activity against Enterobacterales or P. aeruginosa producing metallo-β-lactamase (MBL) or against carbapenemase-producing Acinetobacter baumannii Clinical data regarding the use of these drugs to treat MDR bacteria are limited and rely mostly on nonrandomized studies. An overview on eight BLBLIs in development is also provided. These drugs provide various levels of in vitro coverage of carbapenem-resistant Enterobacterales, with several drugs presenting in vitro activity against MBLs (cefepime-zidebactam, aztreonam-avibactam, meropenem-nacubactam, and cefepime-taniborbactam). Among these drugs, some also present in vitro activity against carbapenem-resistant P. aeruginosa (cefepime-zidebactam and cefepime-taniborbactam) and A. baumannii (cefepime-zidebactam and sulbactam-durlobactam).

Infections Due to Carbapenem-Resistant Bacteria in Patients With Hematologic Malignancies

In developed countries, hematological malignancies (HM) account for 8 to 10% of cancers diagnosed annually and one-third of patients with HM (HMP) are expected to die from their disease. The former wide spectrum “magic bullet,” imipenem, has been ousted by the emergence of carbapenem resistant (CR) pathogens. In endemic areas, infections with CR-bacteria occur in vulnerable patients, notably in HMP, who suffer from high mortality related to infectious complications. In this work, we reviewed epidemiologic and clinical factors associated with CR-infections in adult HMP and data on CR-related mortality and antibiotic treatments in this population. We found that resistance profile of strains involved in HMP infections, mainly bacteremia, reflect local epidemiology. Significant risk factors for infections with CR-bacteria include sex male, age around 50 years old, acute leukemia, selvage chemotherapy, neutropenia, and digestive colonization by CR-bacteria. Mortality rate is high in HMP infected with CR-Enterobacteriaceae, more particularly in case of acute myeloid leukemia and unresolved neutropenia, due to inappropriate empiric management and delayed administration of targeted antibiotics, such as tigecycline, colistin, or new associations of active drugs. Thus, we developed an algorithm for clinicians, assessing the incremental risk for CR-bacterial infection occurrence and mortality in febrile HMP, to guide decisions related to empirical therapeutic strategies.

Ceftazidime/Avibactam and Ceftolozane/Tazobactam for Multidrug-Resistant Gram Negatives in Patients with Hematological Malignancies: Current Experiences

Patients suffering from hematological malignancies are at high risk for severe infections, including in particular bloodstream infections, which represent one of the most frequent life-threatening complications for these patients, with reported mortality rates reaching 40%. Furthermore, a worrisome increase in antimicrobial resistance of Gram-negative bacteria (e.g., cephalosporin- and/or carbapenem-resistant Enterobacteriaceae and multidrug-resistant (MDR) Pseudomonas aeruginosa) involved in severe infectious complications among patients with hematological malignancies has been reported during the last years. The two novel combination of cephalosporins and β-lactamase inhibitors, ceftolozane/tazobactam and ceftazidime/avibactam, were recently approved for treatment of complicated intra-abdominal and urinary tract infections and nosocomial pneumonia and display activity against several MDR Gram-negative strains. Although not specifically approved for neutropenic and/or cancer patients, these drugs are used in this setting due to increasing rates of infections caused by MDR Gram-negative bacteria. The aim of this review is to describe the actual evidence from scientific literature about the "real-life" use of these two novel drugs in patients with hematological malignancies and infections caused by MDR Gram-negative bacteria.

Activity of ceftolozane-tazobactam against Gram-negative pathogens isolated from lower respiratory tract infections in the Asia-Pacific region: SMART 2015-2016

The aim of this study was to investigate the susceptibility of respiratory Gram-negative bacteria to ceftolozane/tazobactam and other antibiotics in the Asia-Pacific region during 2015-2016. MICs were determined using the CLSI standard broth microdilution method and interpreted accordingly. Pseudomonas aeruginosa (1574 isolates), Klebsiella pneumoniae (1226), Acinetobacter baumannii (627) and Escherichia coli (476) accounted for 73.1% of 5342 Gram-negative respiratory pathogens. Susceptibility to ceftolozane/tazobactam of individual Enterobacteriaceae was >80%, except for Enterobacter cloacae (76.6%). Ceftolozane/tazobactam inhibited 81.9% of K. pneumoniae and 91.9% of E. coli, with respective MIC₅₀/MIC₉₀ values of 0.5/>32 and 0.25/2 mg/L. For carbapenem-susceptible, ESBL-producing K. pneumoniae and E. coli, susceptibility was 65.5% and 93.3%, respectively, and respective MIC₅₀/MIC₉₀ values were 2/>32 and 0.5/2 mg/L. Bla_{CTX-M-1 group} was most prevalent in selected ESBL-producing K. pneumoniae (40 of 54 isolates) and E. coli (15 of 22 isolates), with ceftolozane/tazobactam susceptibility rates of 50% and 80%, respectively. Bla_SHV-ESBL was the second most prevalent, and ceftolozane/tazobactam inhibited 20% of 20 K. pneumoniae isolates with bla_SHV-ESBL. The only effective antibiotics for carbapenem-non-susceptible K. pneumoniae (111 isolates) and E. coli (24 isolates) were amikacin and colistin. Ceftolozane/tazobactam was effective against almost all tested P. aeruginosa and carbapenem-non-susceptible strains, with susceptibility of 92.3% and 72.8%, respectively; the respective MIC₅₀/MIC₉₀ values were 1/4 and 2/>32 mg/L. The high susceptibility of ceftolozane/tazobactam remained in different age groups, patient locations, recovery times and countries, except Vietnam. In conclusion, ceftolozane/tazobactam was effective against most respiratory Gram-negative pathogens in the Asia-Pacific region; however, the emergence of carbapenem resistance mandates ongoing surveillance.