A retrospective observational cohort study of the clinical epidemiology of bloodstream infections due to carbapenem-resistant Klebsiella pneumoniae in an OXA-48 endemic setting

Characterization of OXA232-Producing Carbapenem-Resistant Klebsiella pneumoniae: Genomic Analysis and Virulence Assessment

Globally, the infection rate of carbapenem-resistant Klebsiella pneumoniae (CRKP) producing OXA-48-like carbapenemase is increasing, posing a significant public health threat due to its high antibiotic resistance. Between December 2019 and April 2023, ten CRKP strains carrying the OXA-48-like carbapenemase were isolated from inpatients at the First Affiliated Hospital of Kunming Medical University. Wholegenome sequencing (WGS) revealed that all strains carried the OXA-232 gene, a variant of OXA-48-like, located on the non-conjugative ColKP3 plasmid. Sequence typing identified nine strains as ST231 and one as ST11. The ST231 strains carried common virulence genes, including yersiniabactin (ybtA, fyuA, irp2) and aerobactin (iucABCD, iutA), while the ST11 strain carried high-virulence genes (rmpA, rmpA2, peg-344) as well as KPC-2 and OXA-232 carbapenemase genes on separate plasmids, suggesting that CRKP can harbor multiple plasmids with carbapenemase genes. Sequence typing of 264 global ST231 CRKP isolates (n = 264) showed a distinct clonal relationship between our strains and Indian CRKP isolates, indicating potential cross-border transmission. The virulence potential and immune response of the ST231 strains were assessed using a mouse respiratory infection model. The concentrations of inflammatory factors CCL2/MCP-1, IL-6, and TNF-α in the alveolar lavage fluid and blood of the model mice were detected. Combined with the pathological analysis of lung and liver tissues, it reveals variability in virulence and immune response despite carrying identical resistance and virulence genes. This underscores the urgent need for monitoring and tailored public health strategies to combat the global spread of drug-resistant strains.

Antibiotic resistance in the Middle East and Southern Asia: a systematic review and meta-analysis

Introduction

Despite global surveillance efforts, antibiotic resistance (ABR) is difficult to address in low- and middle-income countries (LMICs). In the absence of country-wide ABR surveillance data, peer-reviewed literature is the next most significant source of publicly available ABR data. Médecins Sans Frontières conducted this review in hopes of using the pooled findings to inform treatment choices in the studied countries where sufficient local ABR data are unavailable.

Methods

A systematic literature review reporting ABR rates for six infection sites in nine countries in the Middle East and Southern Asia was conducted. PubMed was used to identify literature published between January 2012 and August 2022. A meta-analysis of the included studies (n = 694) was conducted, of which 224 are reviewed in this paper. The JBI critical appraisal tool was used to evaluate risk of bias for included studies.

Results

This paper focuses on sepsis, burns and wound infections, specifically, with the largest number of papers describing data from Iran, Türkiye and Pakistan. High (>30%) resistance to recommended first-line antibiotics was found. Gram-negative resistance to ceftriaxone, aminoglycosides and carbapenems was high in burn-related infections; colistin resistance among Klebsiella pneumoniae isolates in Pakistan was alarmingly high (81%).

Conclusions

High-quality data on ABR in LMIC settings remain difficult to obtain. While peer-reviewed literature is a source of publicly available ABR data, it is of inconsistent quality; the field also lacks agreed reporting standards, limiting the capacity to pool findings. Nonetheless, high resistance to first-line antibiotics underscores the need for improved localized surveillance and stewardship.

Recent updates in treating carbapenem-resistant infections in patients with hematological malignancies

INTRODUCTION

Patients with hematological malignancies (PHMs) are at increased risk for infections caused by carbapenem-resistant organisms (CROs) due to frequent exposure to broad-spectrum antibiotics and prolonged hospital stays. These infections result in high mortality and morbidity rates along with delays in chemotherapy, longer hospitalizations, and increased health care costs.

AREAS COVERED

Treatment alternatives for CRO infections in PHMs.

EXPERT OPINION

The best available treatment option for KPC and OXA-48 producers is ceftazidime/avibactam. Imipenem/cilastatin/relebactam and meropenem/vaborbactam remain as the alternative options. They can also be used as salvage therapy in KPC-positive Enterobacterales infections resistant to ceftazidime/avibactam, if in vitro susceptibility is shown. Treatment of metallo-β-lactamase producers is an unmet need. Ceftazidime/avibactam plus aztreonam or aztreonam/avibactam seems to be the most reliable option for metallo-β-lactamase producers. As a first-line option for carbapenem-resistant Pseudomonas aeruginosa infections, ceftolozane/tazobactam is preferable and ceftazidime/avibactam and imipenem/cilastatin/relebactam constitute alternative regimens. Although sulbactam/durlobactam is the most reliable option against carbapenem-resistant Acinetobacter baumannii infections, its utility as monotherapy and in PHMs is not yet known. Cefiderocol can be selected as a 'last-resort' option for CRO infections. New risk score models supported by artificial intelligence algorithms can be used to predict the exact risk of infections in previously colonized patients.

Multicenter evaluation of ceftazidime-avibactam use in carbapenem-resistant Klebsiella pneumoniae bloodstream infections in OXA-48 endemic regions

Data in the literature on the use of ceftazidime-avibactam (CAZ-AVI) in carbapenem-resistant Klebsiella pneumoniae bloodstream infections (CRKP-BSIs) are limited especially in OXA-48 (Oxacillinase-48) predominant regions. Our study aimed to evaluate the effect of CAZ-AVI use on outcomes in CRKP-BSIs in Turkey, where OXA-48 is endemic. A multicenter retrospective observational study was conducted between January 2017 and September 2021. The effects of clinical and treatment characteristics on 30-day mortality and relapse in CRKP-BSIs were analyzed. Predictors of outcomes were detected using a Cox regression model. The study enrolled 106 adults with CAZ-AVI-sensitive CRKP-BSIs who received CAZ-AVI for at least 72 h. Patients who received CAZ-AVI as initial therapy had lower mortality rates when compared to those who switched from last resort regimens [14.3% (n = 3/21) vs. 37.7% (n = 32/85), p = 0.04]. In multivariate analysis, older age and severe neutropenia were detected to be associated with higher mortality, significantly. Initiation of CAZ-AVI on the day of blood culture was obtained, was found to be significantly associated with lower mortality (HR: 0.25, CI: 0.07-0.84, p = 0.025). CAZ-AVI monotherapy is an important treatment option for CRKP-BSIs in OXA-48 endemic areas. Early initiation of CAZ-AVI should be preferred rather than switching from a last-resort regimen as it profoundly improves the survival rates.

Outcome of carbapenem or colistin resistant Klebsiella pneumoniae bacteremia in the intensive care unit

Carbapenem-resistant Klebsiella pneumoniae (CRKp) infections continue to be an important cause of mortality. In this retrospective study, the effect of carbapenem or colistin resistance on mortality in Klebsiella pneumoniae bacteremia and combined meropenem + colistin administration in CRKp bacteremia was evaluated. In addition to that, a mathematical model is applied to explore the relationships between the resistance and mortality. A total of 139 adult patients diagnosed with K. pneumoniae bacteremia(73 carbapenem sensitive and 66 carbapenem resistant) between 01/01/2000 and 31/07/2019 were included in the study. The 30-day mortality in entire cohort were 19.4%. 30-day mortality was significantly higher in the carbapenem resistant-colistin sensitive group and in the carbapenem resistant-colistin resistant group compared to the carbapenem susceptible group. Meropenem + colistin combination was administered to 37 (95%) of carbapenem resistant-colistin sensitive (n = 39) and 25 (93%) of carbapenem resistant-colistin resistant patients(n = 27). Notably, mortality was not significantly affected regardless of whether CRKp was colistin sensitive and whether a high dose and prolonged infusion of meropenem was administered. Mortality is higher in carbapenem resistant Klebsiella pneumoniae bacteremia compared to carbapenem susceptible group. In cases of combined meropenem and colistin administration, high dose and prolonged infusion of meropenem is not superior to standard dose and infusion in both carbapenem resistant-colistin sensitive and carbapenem resistant-colistin resistant K. pneumoniae bacteremia.

Mortality factors and antibiotic options in carbapenem-resistant Enterobacterales bloodstream infections: Insights from a high-prevalence setting with co-occurring NDM-1 and OXA-48

Bloodstream infections (BSI) caused by carbapenem-resistant Enterobacterales (CRE) are associated with a high mortality rate. This study aimed to investigate factors associated with 14-day mortality and identify a potential treatment option. A retrospective cohort study was conducted on patients with CRE-BSI in Thailand from 2015 to 2020. The multivariate Cox proportional-hazards model was employed to identify factors influencing 14-day mortality. Out of 134 diagnosed cases of CRE-BSI, the all-cause 14-day mortality rate was 35.1%. The most prevalent organism isolated was Klebsiella pneumoniae (85.8%), followed by Escherichia coli (11.9%). Among the 60 isolates tested for carbapenemase genes, the majority exhibited co-occurring blaNDM-1 and blaOXA-48 (51.7%), followed by blaOXA-48 (31.7%) and blaNDM-1 (15.0%). In the multivariate analysis, neutropenia (adjusted hazard ratio [aHR] 2.55; 95% confidence interval [95%CI] 1.28-5.06; p = 0.008), sepsis/septic shock (aHR 3.02; 95%CI 1.33-6.86; p = 0.008), and previous metronidazole exposures (aHR 3.58; 95%CI 1.89-6.71; p < 0.001) were identified as independent factors for 14-day mortality. The fosfomycin-based regimen was found to be protective (aHR 0.37; 95%CI 0.15-0.92; p = 0.032). In patients with CRE-BSI, particularly in regions with a high occurrence of co-occurring blaNDM-1 and blaOXA-48, neutropenia, sepsis/septic shock, and previous metronidazole exposures emerged as independent risk factors for mortality. Moreover, the fosfomycin-based regimen showed an improvement in the survival rate.

Performance comparison of BD Phoenix CPO detect panel with Cepheid Xpert Carba-R assay for the detection of carbapenemase-producing Klebsiella pneumoniae isolates

BACKGROUND

We aimed to compare the performance of carbapenemase classification in carbapenem-resistant Klebsiella pneumoniae (CRKP) obtained using the BD Phoenix CPO Detect panel (CPO panel) and Cepheid Xpert Carba-R assays. We analyzed 55 CRKP strains from clinical specimens collected between November 2020 and November 2022. The CPO panel was used to detect both antibiotic susceptibility and phenotypic carbapenemase classes, while Xpert Carba-R was employed to identify KPC, NDM, VIM, OXA-48, and IMP genes. Due to the limited availability of molecular kits, we arbitrarily selected 55 isolates, identified as carbapenemase-producing according to the CPO panel and with meropenem minimum inhibitory concentration values > 8 mg/L.

RESULTS

According to the Xpert Carba-R assay, 16 of the 55 isolates (29.1%) were categorised as Ambler Class A (11 of which matched CPO panel Class A identification); three isolates (5.5%) were identified as Class B and 27 isolates (49.1%) as Class D (in both cases consistent with CPO panel B and D classifications). A further eight isolates (14.5%) exhibited multiple carbapenemase enzymes and were designated as dual-carbapenemase producers, while one isolate (1.8%) was identified as a non-carbapenemase-producer. The CPO panel demonstrated positive and negative percent agreements of 100% and 85.7% for Ambler Class A, 100% and 100% for Class B, and 96.4% and 100% for Class D carbapenemase detection, respectively.

CONCLUSION

While the CPO panel's phenotypic performance was satisfactory in detecting Class B and D carbapenemases, additional confirmatory testing may be necessary for Class A carbapenemases as part of routine laboratory procedures.

Monotherapy vs combination therapy in patients with Klebsiella pneumoniae bloodstream infection: A systematic review and meta-analysis

OBJECTIVE

To determine whether mortality is lower in patients with Klebsiella pneumoniae bloodstream infection (BSI) who receive combination antimicrobial therapy than in those who receive monotherapy.

METHODS

Two authors independently searched for relevant articles in the PubMed, Embase, Web of Science, and Cochrane Library databases through to August 10, 2023. Risk of bias was evaluated using the ROBINS-I tool. Possible sources of heterogeneity were evaluated by meta-regression using a mixed-effects model.

RESULTS

Among 8044 articles screened, there were 23 studies (3443 patients) that were eligible for meta-analysis. Meta-regression analysis identified the proportion of patients with carbapenem-resistant Klebsiella pneumoniae (CRKP) BSI to be a potential source of heterogeneity. Subgroup analysis showed that mortality on monotherapy was significantly higher when the proportion of patients with CRKP BSI was ≥50% (OR 1.75, 95% CI 1.33-2.30) and significantly lower when this proportion was <50% (OR 0.55, 95% CI 0.24-1.24). Overall mortality was significantly higher on tigecycline monotherapy (OR 2.86, 95% CI 1.46-5.59) than on combination therapy containing both these agents. There was a trend in favor of colistin/polymyxin B-containing combination therapy (OR 1.37, 95% CI 0.83-2.28).

CONCLUSIONS

Combination antimicrobial therapy can lower mortality in patients with CRKP but may not show a survival advantage over monotherapy when the proportion of patients with CRKP BSI is <50%. High-quality prospective observational studies are needed because of the high risk of bias and limited data in the studies performed to date.

Impact of Immunosuppressed Status on Prognosis of Carbapenem-Resistant Organisms Bloodstream Infections

INTRODUCTION

The impact of immunosuppression on prognosis of carbapenem-resistant organism (CRO) bloodstream infection (BSI) remains unclear. The aim of this study was to clarify the relationship between immunosuppression and mortality of CRO-BSI and to identify the risk factors associated with mortality in immunosuppressed patients.

METHODS

This retrospective study included 279 patients with CRO-BSI from January 2018 to March 2023. Clinical characteristics and outcomes were compared between the immunosuppressed and immunocompetent patients. The relationship between immunosuppression and 30-day mortality after BSI onset was assessed through logistic-regression analysis, propensity score matching (PSM) and inverse probability of treatment weighting (IPTW). Factors associated with mortality in immunosuppressed patients were analyzed using multivariable logistic regression analysis.

RESULTS

A total of 88 immunocompetent and 191 immunosuppressed patients were included, with 30-day all-cause mortality of 58.8%. Although the 30-day mortality in immunosuppressed patients was significantly higher than in immunocompetent patients (46.6% vs. 64.4%, P = 0.007), immunosuppression was not an independent risk factor for mortality in multivariate logistic regression analysis (odds ratio [OR] 3.53, 95% confidence interval [CI] 0.74-18.89; P = 0.123), PSM (OR 1.38, 95% CI 0.60-3.18; P = 0.449,) or IPTW (OR 1.40, 95% CI 0.58-3.36; P = 0.447). For patients with CRO-BSI, regardless of immune status, appropriate antibiotic therapy was associated with decreased 30-day mortality, while Charlson comorbidity index (CCI), intensive care unit (ICU)-acquired infection and thrombocytopenia at CRO-BSI onset were associated with increased mortality.

CONCLUSION

Despite the high mortality rate of CRO-BSI, immunosuppression did not affect the mortality. Appropriate antibiotic therapy is crucial for improving the prognosis of CRO-BSI, regardless of the immune status.

Epidemiology and clinical significance of carbapenemases in Australia: a narrative review

Carbapenemase-producing gram-negative bacteria (CP-GNB) infections threaten public health with high mortality, morbidity and treatment costs. Although frequencies remain low in Australia (total number of CP-GNB infections reported was 907 in 2022), blaIMP-4 has established low levels of endemicity in many states. Imipenemase metallo-β-lactamase types alone accounted for more than half of all carbapenemases in carbapenemase-producing Enterobacterales isolates in Australia, particularly in Enterobacter cloacae complex. New Delhi metallo-β-lactamase constitutes almost 25% of all carbapenemases in Australia and was identified predominantly in Escherichia coli. The OXA-48-like carbapenemases include almost 10% of all carbapenemases and are mainly seen in Klebsiella pneumoniae and E. coli. Although K. pneumoniae carbapenemase-type carbapenemases are rare in Australia, some local outbreaks have occurred. Most carbapenem-resistant (CR) Pseudomonas aeruginosa strains in Australia do not produce carbapenemases. Finally, OXA-23-like carbapenemases are overwhelmingly positive in CR-Acinetobacter baumannii strains in Australia. Treatment of CR-GNB infections challenges physicians. Of 10 new antibiotics active against at least some CR-GNB infections that are approved by the US Food and Drug Administration, just three are approved for use in Australia. In this context, there is still an unmet need for novel antibacterials that can be used for the treatment of CR-GNB infections in Australia, as well as a pressing requirement for new mechanisms to 'de-link' antibiotic sales from their availability. In this narrative review, we aim to overview the epidemiology and clinical significance of carbapenem resistance in Australia as it pertains to Enterobacterales, P. aeruginosa and A. baumannii.

Colistin monotherapy or combination for the treatment of bloodstream infection caused by Klebsiella pneumoniae: a systematic review and meta-analysis

BACKGROUND

Bloodstream infection of Klebsiella pneumoniae (BSI-KP) were associated with increased mortality. Klebsiella pneumoniae was tested to susceptible to colistin by E-test and broth microdilution method in clinical laboratory. This study aimed to assess the efficacy of colistin versus tigecycline, carbapenem monotherapy and combination in the treatment of BSI-KP.

METHODS

Electronic databases such as PubMed, Web of Science and Embase were searched. The last search was in November 24th, 2022, addressing the colistin, carbapenems and tigecycline monotherapy and combination treatments in patients with BSI-KP. The primary outcomes were 30-day or 28-day mortality. OR where available with 95% CI were pooled in random-effects meta-analysis.

RESULTS

Following the outlined search strategy, a total of 658 articles were identified from the initial database searching. Six studies, 17 comparisons were included. However, they all were observational design, lacking high-quality randomized controlled trials (RCTs). Moderate or low-quality evidences suggested that colistin monotherapy was associated with an OR = 1.35 (95% CI = 0.62-2.97, P = 0.45, Tau2 = 0.00, I2 = 0%) compared with tigecycline monotherapy, OR = 0.81 (95% CI = 0.27-2.45, P = 0.71, Tau2 = 0.00, I2 = 0%) compared with carbapenem monotherapy. Compared with combination with tigecycline or carbapenem, Colistin monotherapy resulted in OR of 3.07 (95% CI = 1.34-7.04, P = 0.008, Tau2 = 0.00, I2 = 0%) and 0.98 (95%CI = 0.29-3.31, P = 0.98, Tau2 = 0.00, I2 = 0% ), respectively.

CONCLUSIONS

Colistin, carbapenem and tigecycline monotherapy showed similar treatment effects in patients who suffered from BSI-KP. Compared with colistin monotherapy, colistin combined tigecycline therapy might play the synergism effects.

TRIAL REGISTRATION

retrospectively registered.

Scoping review of risk-scoring tools for early prediction of bloodstream infections caused by carbapenem-resistant Enterobacterales: do we really have a reliable risk-scoring tool?

Background

Bloodstream infections (BSIs) caused by carbapenem-resistant Enterobacterales (CRE) are a global health concern. Rapid identification of CRE may improve patient outcomes and reduce inappropriate antibiotic prescription. The use of risk-scoring tools (RSTs) can be valuable for optimizing the decision-making process for empirical antibiotic therapy of suspected CRE bacteraemia. These tools can also be used to triage use of expensive rapid diagnostic methods.

Methods

We systematically reviewed the relevant literature in PubMed/MEDLINE, CINAHL, Cochrane, Web of Science, Embase and Scopus up to 1 November 2022 to identify RSTs that predict CRE BSIs. The literature review and analysis of the articles were performed by two researchers; any inconsistencies were resolved through discussion.

Results

We identified 9 RSTs developed for early prediction of CRE BSIs and only logistic regression was used for most studies. These RSTs were quite different from each other in terms of their performance and the variables they included. They also had notable limitations and very few of them were externally validated.

Conclusions

RSTs for early prediction of CRE BSIs have limitations and lack of external validity outside the local setting in which they were developed. Future studies to identify optimal RSTs in high and low CRE-endemic settings are warranted. Approaches based on rapid diagnostics and RSTs should be compared with a treatment approach using both methods in a randomized controlled trial.

Ertapenem plus meropenem combination treatment in carbapenem-resistant Klebsiella pneumoniae bacteremia: an analysis of 53 cases

Herein, we aimed to describe the outcomes of patients with blood stream infections due to carbapenem-resistant Klebsiella pneumoniae (CR-Kp) who received ertapenem plus meropenem combination treatment (EMCT). A total of 53 patients with culture proven CR-Kp bacteremia treated with ertapenem + meropenem were included. The patients with secondary bacteremia due to urinary tract infection exhibited a significantly lower 1-month mortality (OMM), particularly in those with microbiological eradication and those with end-of-treatment success. Salvage EMCT resulted in 49% 1-month survival.

In vitro, in vivo and clinical studies comparing the efficacy of ceftazidime-avibactam monotherapy with ceftazidime-avibactam-containing combination regimens against carbapenem-resistant Enterobacterales and multidrug-resistant Pseudomonas aeruginosa isolates or infections: a scoping review

Introduction

Carbapenem-resistant Enterobacterales (CRE) and multidrug-resistant Pseudomonas aeruginosa (MDR-PA) infections are associated with a high risk of morbidity, mortality, and treatment costs. We aimed to evaluate in vitro, in vivo and clinical studies comparing the efficacy of ceftazidime-avibactam (CZA) combination regimens with CZA alone against CRE and/or MDR-PA isolates or infections.

Methods

We systematically reviewed the relevant literature in CINAHL/MEDLINE, Pubmed, Cochrane, Web of Science, Embase, and Scopus until December 1, 2022. Review articles, grey literature, abstracts, comments, editorials, non-peer reviewed articles, non-English articles, and in vitro synergy studies conducted on single isolates were excluded.

Results

22 in vitro, 7 in vivo and 20 clinical studies were evaluated. In vitro studies showed reliable synergy between CZA and aztreonam against metallo-β-lactamase (MBL)-producing isolates. Some studies indicated good in vitro synergy between CZA and amikacin, meropenem, fosfomycin and polymyxins against CRE isolates. For MDR-PA isolates, there are comparatively fewer in vitro or in vivo studies. In observational clinical studies, mortality, clinical cure, adverse events, and development of CZA resistance after exposure were generally similar in monotherapy and combination therapy groups. However, antibiotic-related nephrotoxicity and infection relapses were higher in patients receiving CZA combination therapies.

Discussion

The benefit, if any, of CZA combination regimens in MDR-PA infections is elusive, as very few clinical studies have included these infections. There is no currently documented clinical benefit for the use of CZA combination regimens rather than CZA monotherapy. CZA combined with aztreonam for serious infections due to MBL producers should be evaluated by randomized controlled trials.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=278552, CRD42021278552.

Next-Generation Polymyxin Class of Antibiotics: A Ray of Hope Illuminating a Dark Road

Although new-generation antimicrobials, in particular β-lactam/β-lactamase inhibitors, have largely replaced polymyxins in carbapenem-resistant Gram-negative bacterial infections, polymyxins are still needed for carbapanem-resistant Acinetobacter baumannii infections and in settings where novel agents are not readily available. Despite their potent in vitro activity, the clinical utility of polymyxins is significantly limited by their pharmacokinetic properties and nephrotoxicity risk. There is significant interest, therefore, in developing next-generation polymyxins with activity against colistin-resistant strains and lower toxicity than existing polymyxins. In this review, we aim to present the antibacterial activity mechanisms, in vitro and in vivo efficacy data, and toxicity profiles of new-generation polymyxins, including SPR206, MRX-8, and QPX9003, as well as the general characteristics of old polymyxins. Considering the emergence of colistin-resistant strains particularly in endemic regions, the restoration of the antimicrobial activity of polymyxins via PBT2 is also described in this review.

Treatment strategies for OXA-48-like and NDM producing Klebsiella pneumoniae infections

INTRODUCTION

OXA-48 and NDM are amongst the most prevalent carbapenemase types associated with Klebsiella pneumoniae worldwide, with an increase in their prevalence in recent years. Knowledge on the treatment of carbapenem-resistant Klebsiella pneumoniae (CRKP) comes from KPC-producing CRKP with limited data available for OXA-48-like and NDM producers. Our aim is to review the literature on the treatment of OXA-48-like and NDM-producing CRKP with the goal of providing an update on the available antibiotic treatment strategies, particularly in light of changing carbapenemase epidemiology and increasing antimicrobial resistance.

AREAS COVERED

We reviewed studies looking at the antibiotic treatment and outcome of OXA-48-like and/or NDM-producing CRKP.

EXPERT OPINION

The best available treatment option for OXA-48 producers is ceftazidime-avibactam, where available and when the price permits its use. Colistin remains as the second-line option if in vitro susceptibility is demonstrated with an appropriate method. There is not enough evidence to support the use of meropenem-containing combination therapies for meropenem-resistant OXA-48 producers. Treatment of NDM producers is an unmet need. Ceftazidime-avibactam and aztreonam combination or cefiderocol can be used for NDM producers, where available. Higher cefiderocol MICs against NDM producers is concerning. Aztreonam-avibactam provides hope for the treatment of NDM producers.

Piperacillin–Tazobactam Plus Vancomycin-Associated Acute Kidney Injury in Adults: Can Teicoplanin or Other Antipseudomonal Beta-Lactams Be Remedies?

Numerous observational studies and meta-analyses have suggested that combination therapy consisting of piperacillin–tazobactam (TZP) and vancomycin (VAN) augments acute kidney injury (AKI) risk when compared to viable alternatives, such as cefepime–vancomycin (FEP–VAN) and meropenem–VAN. However, the exact pathophysiological mechanisms of this phenomenon are still unclear. One major limitation of the existing studies is the utilization of serum creatinine to quantify AKI since serum creatinine is not a sufficiently sensitive and specific biomarker to truly define the causal relationship between TZP–VAN exposure and nephrotoxicity. Even so, some preventive measures can be taken to reduce the risk of AKI when TZP–VAN is preferred. These measures include limiting the administration of TZP–VAN to 72 h, choosing FEP–VAN in place of TZP–VAN in appropriate cases, monitoring the VAN area under the curve level rather than the VAN trough level, avoiding exposure to other nephrotoxic agents, and minimizing the prescription of TZP–VAN for patients with a high risk of AKI. More data are needed to comment on the beneficial impact of the extended-infusion regimen of TZP on nephrotoxicity. Additionally, TZP and teicoplanin can be reasonable alternatives to TZP–VAN for the purpose of lowering AKI risk. However, the data are scarce to advocate this practice convincingly.