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Antimicrobial Agents and Chemotherapy Dec 2023Cefiderocol is a siderophore cephalosporin that binds ferric iron and utilizes iron transporters to cross the cell membrane. Hypervirulent (hvKp) is known to produce...
Cefiderocol is a siderophore cephalosporin that binds ferric iron and utilizes iron transporters to cross the cell membrane. Hypervirulent (hvKp) is known to produce more siderophores; in this case, the uptake of cefiderocol may be decreased. Therefore, the objective of this study was to evaluate the activity of cefiderocol against hvKp isolates. A total of 320 carbapenem-resistant (CRKp) isolates were collected in China between 2014 and 2022, including 171 carbapenem-resistant hvKp (CR-hvKp) and 149 carbapenem-resistant classical (CR-cKp). Quantitative detection of siderophores showed that the average siderophore production of CR-hvKp (234.6 mg/L) was significantly higher than that of CR-cKp (68.9 mg/L, < 0.001). The overall cefiderocol resistance rate of CR-hvKp and CR-cKp was 5.8% (10/171) and 2.7% (4/149), respectively. The non-susceptible rates of both cefiderocol and siderophore production of CR-hvKp isolates were higher than those of CR-cKp in either NDM-1- or KPC-2-producing groups. The MIC90 and MIC50 for CR-hvKp and CR-cKp were 8 mg/L and 2 mg/L and 4 mg/L and 1 mg/L, respectively. The cumulative cefiderocol MIC distribution for CR-hvKp was significantly lower than that of CR-cKp isolates ( = 0.003). KL64 and KL47 consisted of 53.9% (83/154) and 75.7% (53/70) of the ST11 CR-hvKp and CR-cKp, respectively, and the former had significantly higher siderophore production. In summary, cefiderocol might be less effective against CR-hvKp compared with CR-cKp isolates, highlighting the need for caution regarding the prevalence of cefiderocol-resistant strains, particularly in CR-hvKp isolates.
Topics: Humans; Cephalosporins; Cefiderocol; Siderophores; Klebsiella pneumoniae; Klebsiella Infections; Carbapenems; Monobactams; China; Iron; Carbapenem-Resistant Enterobacteriaceae; Anti-Bacterial Agents
PubMed: 38014944
DOI: 10.1128/aac.00735-23 -
The Journal of Antimicrobial... Oct 2023Critically ill patients have increased variability in beta-lactam antibiotic (beta-lactam) exposure due to alterations in their volume of distribution and elimination.... (Review)
Review
Critically ill patients have increased variability in beta-lactam antibiotic (beta-lactam) exposure due to alterations in their volume of distribution and elimination. Therapeutic drug monitoring (TDM) of beta-lactams, as a dose optimization and individualization tool, has been recommended to overcome this variability in exposure. Despite its potential benefit, only a few centres worldwide perform beta-lactam TDM. An important reason for the low uptake is that the evidence for clinical benefits of beta-lactam TDM is not well established. TDM also requires the availability of specific infrastructure, knowledge and expertise. Observational studies and systematic reviews have demonstrated that TDM leads to an improvement in achieving target concentrations, a reduction in potentially toxic concentrations and improvement of clinical and microbiological outcomes. However, a small number of randomized controlled trials have not shown a mortality benefit. Opportunities for improved study design are apparent, as existing studies are limited by their inclusion of heterogeneous patient populations, including patients that may not even have infection, small sample size, variability in the types of beta-lactams included, infections caused by highly susceptible bacteria, and varied sampling, analytical and dosing algorithm methods. Here we review the fundamentals of beta-lactam TDM in critically ill patients, the existing clinical evidence and the practical aspects involved in beta-lactam TDM implementation.
Topics: Humans; Anti-Bacterial Agents; Drug Monitoring; Critical Illness; beta-Lactams; Critical Care; Monobactams
PubMed: 37466209
DOI: 10.1093/jac/dkad223 -
The Journal of Antimicrobial... Nov 2023The new definitions of antimicrobial susceptibility categories proposed by EUCAST in 2020 require the definition of standard and high dosages of antibiotic. For...
BACKGROUND
The new definitions of antimicrobial susceptibility categories proposed by EUCAST in 2020 require the definition of standard and high dosages of antibiotic. For injectable β-lactams, standard and high dosages have been proposed for short-infusion regimens only.
OBJECTIVES
To evaluate dosages for β-lactams administered by prolonged infusion (PI) and continuous infusion (CI).
METHODS
Monte Carlo simulations were performed for seven injectable β-lactams: aztreonam, cefepime, cefotaxime, cefoxitin, ceftazidime, piperacillin and temocillin. Various dosage regimens based on short infusion, PI or CI were simulated in virtual patients. Pharmacokinetic (PK) profiles and PTAs were obtained based on reference population PK models, as well as PK/pharmacodynamic targets and MIC breakpoints proposed by EUCAST. Alternative dosage regimens associated with PTA values similar to those of recommended dosages up to the breakpoints were considered acceptable.
RESULTS
Adequate PTAs were confirmed for most EUCAST short-infusion dosage regimens. A total of 9 standard and 14 high dosages based on PI (3 to 4 h) or CI were identified as alternatives. For cefepime and aztreonam, only PI and CI regimens could achieve acceptable PTAs for infections caused by Pseudomonas spp.: 2 g q8h as PI of 4 h or 6 g/24 h CI for cefepime; 2 g q6h as PI of 3 h or 6 g/24 h CI for aztreonam.
CONCLUSIONS
These alternative standard and high dosage regimens are expected to provide antibiotic exposure compatible with new EUCAST definitions of susceptibility categories and associated MIC breakpoints. However, further clinical evaluation is necessary.
Topics: Humans; Cefepime; Aztreonam; Anti-Bacterial Agents; Ceftazidime; Piperacillin; Microbial Sensitivity Tests; Monte Carlo Method
PubMed: 37796958
DOI: 10.1093/jac/dkad300 -
Critical Reviews in Microbiology Aug 2023Treatment to common bacterial infections are becoming ineffective of late, owing to the emergence and dissemination of antibiotic resistance globally. and are the most... (Review)
Review
Treatment to common bacterial infections are becoming ineffective of late, owing to the emergence and dissemination of antibiotic resistance globally. and are the most notorious microorganisms and are among the critical priority pathogens listed by WHO in 2017. These pathogens are the predominant cause of sepsis, urinary tract infections (UTIs), pneumonia, meningitis and pyogenic liver abscess. Concern arises due to the resistance of bacteria to most of the beta lactam antibiotics like penicillin, cephalosporin, monobactams and carbapenems, even to the last resort antibiotics like colistin. Preventing influx by modulation of porins, extruding the antibiotics by overexpression of efflux pumps, mutations of drug targets/receptors, biofilm formation, altering the drug molecules and rendering them ineffective are few resistance mechanisms that are adapted by upon exposure to antibiotics. The situation is exacerbated due to the process of horizontal gene transfer (HGT), wherein the genes encoding resistance mechanisms are transferred to the neighbouring bacteria through plasmids/phages/uptake of free DNA. Carbapenemases, other beta lactamases and genes coding for colistin resistance are widely disseminated leading to limited/no therapeutic options against those infections. Development of new antibiotics can be viewed as a possible solution but it involves major investment, time and labour despite which, the bacteria can easily adapt to the new antibiotic and evolve resistance in a relatively short time. Targeting the resistance mechanisms can be one feasible alternative to tackle these multidrug resistant (MDR) pathogens. Removal of plasmid (plasmid curing) causing resistance, use of bacteriophages and bacteriotherapy can be other potential approaches to combat infections caused by MDR and . The present review discusses the efficacies of these therapies in mitigating these infections, which can be potentially used as an adjuvant therapy along with existing antibiotics.
Topics: Enterobacteriaceae; Escherichia coli; Klebsiella pneumoniae; Colistin; Anti-Bacterial Agents; Bacterial Proteins; beta-Lactamases; Plasmids; Monobactams; Drug Resistance; Microbial Sensitivity Tests; Drug Resistance, Bacterial
PubMed: 35649163
DOI: 10.1080/1040841X.2022.2080525 -
The Journal of Antimicrobial... Jul 2023Cefepime and aztreonam are highly efficacious against H. influenzae, and resistant strains are rare. In this study, we isolated cefepime- and aztreonam-nonsusceptible H....
BACKGROUND
Cefepime and aztreonam are highly efficacious against H. influenzae, and resistant strains are rare. In this study, we isolated cefepime- and aztreonam-nonsusceptible H. influenzae strains and addressed the molecular basis of their resistance to cefepime and aztreonam.
METHODS
Two hundred and 28 specimens containing H. influenzae were screened, of which 32 isolates were enrolled and applied to antimicrobial susceptibility testing and whole-genome sequencing. Genetic variations that were detected in all nonsusceptible isolates with statistical significance by Fisher's exact tests were identified as cefepime or aztreonam nonsusceptibility related. Functional complementation assays were conducted to assess the in vitro effects of proteins with sequence substitutions on drug susceptibility.
RESULTS
Three H. influenzae isolates were nonsusceptible to cefepime, one of which was also nonsusceptible to aztreonam. Genes encoding TEM, SHV and CTX-M extended-spectrum β-lactamases were not detected in the cefepime- and aztreonam-nonsusceptible isolates. Five genetic variations in four genes and 10 genetic variations in five genes were associated with cefepime and aztreonam nonsusceptibility, respectively. Phylogenetic analyses revealed that changes in FtsI were correlated strongly with the MIC of cefepime and moderately with aztreonam. FtsI Thr532Ser-Tyr557His cosubstitution linked to cefepime nonsusceptibility and Asn305Lys-Ser385Asn-Glu416Asp cosubstitution to aztreonam nonsusceptibility. Functional complementation assays revealed that these cosubstitutions increased MICs of cefepime and aztreonam in susceptible H. influenzae isolates, respectively.
CONCLUSIONS
Genetic variations relevant to resistant phenotypes of cefepime and aztreonam nonsusceptibility in H. influenzae were identified. Moreover, the effects of FtsI cosubstitutions on increasing MICs of cefepime and aztreonam in H. influenzae were demonstrated.
Topics: Cefepime; Aztreonam; Haemophilus influenzae; Phylogeny; beta-Lactamases; Microbial Sensitivity Tests; Anti-Bacterial Agents
PubMed: 37210083
DOI: 10.1093/jac/dkad137 -
Journal of Clinical Microbiology Oct 2023Aztreonam-avibactam (AZA), a newly developed β-lactam/β-lactamase inhibitor combination is a treatment option for infections due to carbapenem-resistant...
Aztreonam-avibactam (AZA), a newly developed β-lactam/β-lactamase inhibitor combination is a treatment option for infections due to carbapenem-resistant Enterobacterales (CRE), including metallo-ß-lactamase producers, regardless of additional production of broad-spectrum serine-ß-lactamases. However, AZA-resistance has already been reported in Enterobacterales and its early detection could be a valuable tool for faster and more accurate clinical decision-making. We therefore developed a rapid culture-based test for the identification of AZA resistance among multidrug-resistant Enterobacterales. The Rapid Aztreonam/Avibactam NP test is based on resazurin reduction when bacterial growth occurs in the presence of AZA at 8/4 µg/mL (protocol 1) or 12/4 µg/mL (protocol 2). Given the absence of guidelines on AZA susceptibility testing, two tentative breakpoints were indeed used to categorize AZA-susceptible isolates: ≤4 µg/mL in protocol 1 and ≤ 8 µg/mL in protocol 2. Bacterial growth was visually detectable by a blue-to-purple or blue-to-pink color change of the medium. A total of 78 enterobacterial isolates (among which 34 AZA-resistant and 13 AZA-resistant according to protocols 1 and 2, respectively) were used to evaluate the test performance using protocol 1 or protocol 2. The sensitivity and specificity of the test were found to be 100% and 97.7%, respectively, following protocol 1 and 100% and 100%, respectively, following protocol 2, in comparison with broth microdilution. All results were obtained within 4.5 hours corresponding to a time saving of ca. 14 hours compared with currently available methods for AZA susceptibility testing. The Rapid Aztreonam/Avibactam NP test is rapid, highly sensitive, specific, easily interpretable, and easy to implement in routine.
Topics: Humans; Aztreonam; Anti-Bacterial Agents; beta-Lactamases; Azabicyclo Compounds; beta-Lactamase Inhibitors; Microbial Sensitivity Tests; Drug Combinations; Ceftazidime
PubMed: 37791761
DOI: 10.1128/jcm.00588-23 -
Expert Opinion on Therapeutic Patents Mar 2021Monocyclic beta-lactams are four-membered cyclic amides with various structural modifications of the nucleus that determine their chemical reactivity and target... (Review)
Review
INTRODUCTION
Monocyclic beta-lactams are four-membered cyclic amides with various structural modifications of the nucleus that determine their chemical reactivity and target specificity. Their historical use is based on their antibacterial activity, but they have recently appeared in other areas as well.
AREAS COVERED
This review summarizes the relevant patent development on monocyclic beta-lactams in various therapeutic areas over the last 10 years. The majority of patents describe compounds with antibacterial activity, while there are some recent patents describing the neuroprotective, anti-inflammatory, anti-cancer, anticoagulant and antihyperlipidemic effects of 2-azetidinones.
EXPERT OPINION
Monocyclic beta-lactams can be considered safe and nontoxic drugs, as they have been used in the clinic for almost half of the century. Recently, monocyclic beta-lactams have been increasingly recognized for their non-antibiotic activity, which has led to some promising new clinical candidates in the field of neurodegenerative diseases and coagulation therapy. With regard to their antibacterial activity, there is still room for improvement of their activity and broadening of their spectrum of action, especially in Gram-positive bacteria and on drug-insensitive penicillin-binding proteins, and in increasing their beta-lactamase stability.
Topics: Animals; Anti-Bacterial Agents; Anticoagulants; Drug Development; Humans; Monobactams; Neurodegenerative Diseases; Patents as Topic; Structure-Activity Relationship
PubMed: 33327805
DOI: 10.1080/13543776.2021.1865919 -
The Journal of Allergy and Clinical... Aug 2023A guideline identifying when inpatients with penicillin or cephalosporin antibiotic allergy labels (PCAAL) can receive β-lactam antibiotics increased β-lactam receipt...
BACKGROUND
A guideline identifying when inpatients with penicillin or cephalosporin antibiotic allergy labels (PCAAL) can receive β-lactam antibiotics increased β-lactam receipt at a large northeastern US health care system.
OBJECTIVE
To report outcomes of implementing a similar guideline and electronic order set (OS) at an independent academic health care system.
METHODS
Penicillin/cephalosporin receipt (percentage of inpatients receiving full doses) and alternative antibiotic use (days of therapy per 1000 patient-days [DOT/1000PD]) were compared over 3 periods before (February 1, 2017, to January 31, 2018) and after guideline implementation (February 1, 2018, to January 31, 2019), and after OS implementation (February 1, 2019, to January 31, 2020) among inpatients with PCAAL admitted on medical services with access to guideline/OS and education (Medical-PCAAL, n = 8721), surgical services with access to guideline/OS without education (Surgical-PCAAL, n = 5069), and obstetrics/gynecology services without interventions (Ob/Gyn-PCAAL, n = 798) and inpatients without PCAAL admitted on the same services (Medical-No-PCAAL, n = 50,840; Surgical-No-PCAAL, n = 29,845; Ob/Gyn-No-PCAAL, n = 6109). χ tests were used to compare categorical variables, and analysis of variance was used to compare continuous and interrupted time series analyses (ITSA) to investigate the guideline/OS implementation effect on penicillin/cephalosporin receipt.
RESULTS
In the Medical-PCAAL group, penicillin/cephalosporin receipt increased (58%-68%, P < .001), specifically for cefazolin (8%-11%, P = .02) and third- to fifth-generation cephalosporins (43%-48%, P = .04), and aztreonam use decreased (12 DOT/1000PD, P = .03). In the Medical-No-PCAAL group, penicillin/cephalosporin receipt increased (88%-90%, P = .004), specifically for penicillin (40%-44%, P < .001), without changes in aztreonam use. Significant changes were not observed in these outcomes on surgical or obstetrics/gynecology services. Per ITSA, guideline/OS implementation was associated with increased penicillin/cephalosporin receipt in the Medical-PCAAL group only.
CONCLUSION
Guideline and OS implementation was associated with improved antibiotic stewardship on inpatient services that also received allergy education.
Topics: Humans; Anti-Bacterial Agents; beta-Lactams; Inpatients; Aztreonam; Penicillins; Cephalosporins; Drug Hypersensitivity; Hypersensitivity; Retrospective Studies
PubMed: 37182569
DOI: 10.1016/j.jaip.2023.04.051 -
The Journal of Infection Sep 2023The optimisation of the use of β-lactam antibiotics (BLA) via prolonged infusions in life-threatening complications such as febrile neutropenia (FN) is still... (Meta-Analysis)
Meta-Analysis
BACKGROUND
The optimisation of the use of β-lactam antibiotics (BLA) via prolonged infusions in life-threatening complications such as febrile neutropenia (FN) is still controversial. This systematic review and meta-analysis aim to evaluate the efficacy of this strategy in onco-haematological patients with FN.
METHODS
A systematic search was performed of PubMed, Web of Science, Cochrane, EMBASE, World Health Organization, and ClinicalTrials.gov, from database inception until December 2022. The search included randomised controlled trials (RCTs) and observational studies that compared prolonged vs short-term infusions of the same BLA. The primary outcome was all-cause mortality. Secondary outcomes were defervescence, requirement of vasoactive drugs, length of hospital stay and adverse events. Pooled risk ratios were calculated using random effects models.
RESULTS
Five studies were included, comprising 691 episodes of FN, mainly in haematological patients. Prolonged infusion was not associated with a reduction in all-cause mortality (pRR 0.83; 95% confidence interval 0.47-1.48). Nor differences were found in secondary outcomes.
CONCLUSIONS
The limited data available did not show significant differences in terms of all-cause mortality or significant secondary outcomes in patients with FN receiving BLA in prolonged vs. short-term infusion. High-quality RCTs are needed to determine whether there are subgroups of FN patients who would benefit from prolonged BLA infusion.
Topics: Humans; Anti-Bacterial Agents; Monobactams; Febrile Neutropenia
PubMed: 37423503
DOI: 10.1016/j.jinf.2023.06.023 -
European Journal of Neurology Dec 2023Evidence-based recommendations for treatment of Lyme neuroborreliosis (LNB) should rely on the available literature. As new data emerges, close review and evaluation of... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Evidence-based recommendations for treatment of Lyme neuroborreliosis (LNB) should rely on the available literature. As new data emerges, close review and evaluation of the recent literature is needed to build evidence-based recommendations to inform clinical practice and management of LNB. We performed an update of a previous systematic review on treatment of LNB.
METHODS
A systematic literature search of Medline and CENTRAL was performed for published studies from 2015 to 2023 to update a previous systematic review. Randomized controlled trials (RCTs) and non-randomized studies (NRS) were evaluated. Risk of bias was assessed using the Cochrane risk of bias tools for RCTs; NRS were assessed using the ROBINS-I-tool. Quality of the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Data were integrated into an existing meta-analysis of the available literature.
RESULTS
After screening 1530 records, two RCTs and five NRS with new and relevant data were additionally identified. Meta-analysis showed no statistically significant difference between doxycycline and beta-lactam antibiotics regarding residual neurological symptoms after 12 months. Meta-analysis showed no benefit of extended antibiotic treatment of LNB. Three NRS show no benefit for additional steroid use in LNB with facial palsy.
DISCUSSION
Additional incorporated recent research corroborates existing guideline recommendations for treatment of LNB. New RCTs add to the certainty of previous analysis showing similar efficacy for doxycycline and beta-lactam antibiotics in LNB. Available evidence shows no benefit for extended antibiotic treatment in LNB. NRS do not suggest a role for steroids in facial palsy due to LNB.
Topics: Humans; Lyme Neuroborreliosis; Doxycycline; Facial Paralysis; Anti-Bacterial Agents; Monobactams
PubMed: 37565386
DOI: 10.1111/ene.16034