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Antimicrobial Agents and Chemotherapy Nov 2022Several pathophysiological changes can alter meropenem pharmacokinetics in critically ill patients, thereby increasing the risk of subtherapeutic concentrations and...
Several pathophysiological changes can alter meropenem pharmacokinetics in critically ill patients, thereby increasing the risk of subtherapeutic concentrations and affecting therapeutic outcomes. This study aimed to characterize the population pharmacokinetic (PPK) parameters of meropenem, evaluate the relationship between the pharmacokinetic/pharmacodynamic index of meropenem and treatment outcomes, and evaluate the different dosage regimens that can achieve 40%, 75%, and 100% of the dosing interval for which the free plasma concentrations remain above the MIC of the pathogens () targets. Critically ill adult patients treated with meropenem were recruited for this study. Five blood samples were collected from each patient. PPK models were developed using a nonlinear mixed-effects modeling approach, and the final model was subsequently used for Monte Carlo simulations to determine the optimal dosage regimens. A total of 247 concentrations from 52 patients were available for analysis. The two-compartment model with linear elimination adequately described the data. The mean PPK parameters were clearance (CL) of 4.8 L/h, central volume of distribution (V) of 11.4 L, peripheral volume of distribution (V) of 14.6 L, and intercompartment clearance of 10.5 L/h. Creatinine clearance was a significant covariate affecting CL, while serum albumin level and shock status were factors influencing V and V, respectively. Although 75% of the drug-resistant infection patients had values of >40%, approximately 83% of them did not survive the infection. Therefore, 40% might not be sufficient for critically ill patients, and a higher target, such as 75 to 100% , should be considered for optimizing therapy. A 75% could be reached using approved doses administered via a 3-h infusion.
Topics: Humans; Adult; Meropenem; Critical Illness; Anti-Bacterial Agents; Monte Carlo Method; Microbial Sensitivity Tests
PubMed: 36226944
DOI: 10.1128/aac.00845-22 -
Antimicrobial Agents and Chemotherapy May 2023Dissemination of hypervirulent and carbapenem-resistant Klebsiella pneumoniae (CRKP) has been reported worldwide, posing a serious threat to antimicrobial therapy and...
Dissemination of hypervirulent and carbapenem-resistant Klebsiella pneumoniae (CRKP) has been reported worldwide, posing a serious threat to antimicrobial therapy and public health. Outer membrane vesicles (OMVs) act as vectors for the horizontal transfer of virulence and resistance genes. However, K. pneumoniae OMVs that transfer carbapenem resistance genes into hypervirulent K. pneumoniae (hvKP) have been insufficiently investigated. Therefore, this study investigates the transmission of the gene encoding resistance via OMVs released from CRKP and the potential mechanism responsible for the carbapenem-resistant hypervirulent K. pneumoniae (CR-hvKP) emergence. OMVs were isolated via ultracentrifugation from CRKP with or without meropenem selective pressure. OMVs were then used to transform classical K. pneumoniae (ckp) ATCC 10031, extended-spectrum β-lactamase (ESBL)-producing K. pneumoniae ATCC 700603, and hvKP NTUH-K2044. Our results showed that meropenem treatment resulted in changes in the number and diameter of OMVs secreted by CRKP. OMVs derived from CRKP mediated the transfer of to ckp and hvKP, thereby increasing the carbapenem MIC of transformants. Further experiments confirmed that NTUH-K2044 transformants exhibited hypervirulence. Our study demonstrates, for the first time, that OMVs derived from CRKP can carry and deliver resistance genes to other K. pneumoniae strains, even hvKP. The transfer of carbapenem genes into hypervirulent strains may promote the emergence and dissemination of CR-hvKP. This study elucidates a new mechanism underlying the formation of CR-hvKP.
Topics: Humans; Klebsiella pneumoniae; Meropenem; Klebsiella Infections; Carbapenems; Anti-Bacterial Agents; Carbapenem-Resistant Enterobacteriaceae
PubMed: 37052502
DOI: 10.1128/aac.01444-22 -
Acta Microbiologica Et Immunologica... Jun 2023The incidence of infections caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) is increasing worldwide, and very limited number of effective antibiotics are...
The incidence of infections caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) is increasing worldwide, and very limited number of effective antibiotics are available for therapy. In our study, the in vitro efficacy of meropenem/polymyxin B and meropenem/fosfomycin combinations against CRKP strains was investigated. The efficiency of meropenem/polymyxin B and meropenem/fosfomycin combinations was tested by checkerboard microdilution and checkerboard agar dilution methods, respectively, against 21 CRKP strains containing major carbapenem resistant genes (7 blaKPC, 7 blaOXA-48 gene, and 7 blaOXA-48+ blaNDM), and seven additional CRKP strains without carbapenemase genes.Among the 28 CRKP strains, the meropenem/polymyxin B combination was synergistic in ten (35.7%), partially synergistic in 12 (42.8%), and indifferent in six (21.4%) isolates. The meropenem/fosfomycin combination was found to be synergistic in three isolates (10.7%), partially synergistic in 20 (71.4%), and indifferent in five (17.8%). In 21 strains containing carbapenem resistance genes, meropenem/polymyxin B and meropenem/fosfomycin combinations exhibited synergistic/partial synergistic effects in 15 (71.4%) and 16 (76.2%) strains, respectively, compared to 100% synergistic/partial synergistic efficiency in both combinations in seven strains free of carbapenemase genes. No antagonistic effect was detected in either combination.Regardless of presence or absence of carbapenem resistance genes, meropenem/polymyxin B and meropenem/fosfomycin combinations both demonstrated high synergistic and partial synergistic activity against 78.4% and 82.1% of CRKP strains, respectively. Also, they have no antagonistic effects and can be used successfully to prevent therapeutic failure with monotherapy, according to our in vitro studies.
Topics: Humans; Meropenem; Fosfomycin; Polymyxin B; Klebsiella pneumoniae; Anti-Bacterial Agents; Carbapenem-Resistant Enterobacteriaceae; Carbapenems; beta-Lactamases; Microbial Sensitivity Tests; Klebsiella Infections
PubMed: 37133999
DOI: 10.1556/030.2023.02015 -
Peritoneal Dialysis International :... 2018Infections caused by ceftazidime-resistant and extended-spectrum beta-lactamase (ESBL)-producing gram-negative bacteria are increasing worldwide. Meropenem and...
BACKGROUND
Infections caused by ceftazidime-resistant and extended-spectrum beta-lactamase (ESBL)-producing gram-negative bacteria are increasing worldwide. Meropenem and piperacillin/tazobactam (PIP/TZB) are recommended for the treatment of peritoneal dialysis-associated peritonitis (PDAP) caused by ceftazidime-resistant and other resistant gram-negative bacteria. Patients may also receive intraperitoneal heparin to prevent occlusion of their catheters. However, the stability of meropenem or PIP/TZB, in combination with heparin, in different types of peritoneal dialysis (PD) solutions used in clinical practice is currently unknown. Therefore, we investigated the stability of meropenem and PIP/TZB, each in combination with heparin, in different PD solutions.
METHODS
A total of 15 PD bags (3 bags for each type of PD solution) containing meropenem and heparin and 24 PD bags (3 bags for each type of PD solution) containing PIP/TZB and heparin were prepared and stored at 4°C for 168 hours. The same bags were stored at 25°C for 3 hours followed by 10 hours at 37°C. An aliquot withdrawn before storage and at defined time points was analyzed for the concentration of meropenem, PIP, TZB, and heparin using high-performance liquid chromatography. Samples were also analysed for particle content, pH and color change, and the anticoagulant activity of heparin.
RESULTS
Meropenem and heparin retained more than 90% of their initial concentration in 4 out of 5 types of PD solutions when stored at 4°C for 168 hours, followed by storage at 25°C for 3 hours and then at 37°C for 10 hours. Piperacillin/tazobactam and heparin were found to be stable in all 8 types of PD solutions when stored under the same conditions. Heparin retained more than 98% of its initial anticoagulant activity throughout the study period. No evidence of particle formation, color change, or pH change was observed at any time under the storage conditions employed in the study.
CONCLUSIONS
This study provides clinically important information on the stability of meropenem and PIP/TZB, each in combination with heparin, in different PD solutions. The use of meropenem-heparin admixed in pH-neutral PD solutions for the treatment of PDAP should be avoided, given the observed suboptimal stability of meropenem.
Topics: Catheter-Related Infections; Ceftazidime; Chromatography, High Pressure Liquid; Dialysis Solutions; Drug Stability; Female; Heparin; Humans; Male; Meropenem; Peritoneal Dialysis; Piperacillin, Tazobactam Drug Combination; Sensitivity and Specificity
PubMed: 29991562
DOI: 10.3747/pdi.2017.00274 -
Molecular Immunology Aug 2022Multi-drug resistant Pseudomonas aeruginosa is a gram-negative bacillus responsible for nosocomial infections. Immunoglobulin Y (IgY) is a chicken immunoglobulin used...
Multi-drug resistant Pseudomonas aeruginosa is a gram-negative bacillus responsible for nosocomial infections. Immunoglobulin Y (IgY) is a chicken immunoglobulin used for research, immunodiagnosis, and immunotherapy. IgY presents antimicrobial properties and it is under investigation for use as an adjunct to prophylactic therapies. The current study aimed to assess the synergistic action between anti-P aeruginosa IgY and the beta-lactams ceftazidime, imipenem, and meropenem. IgY antibodies were obtained from laying hens immunized with SPM-1 producing P. aeruginosa (Pa48) or VIM-2 producing P. aeruginosa (Pa23). The antimicrobial activity of IgY antibodies was evaluated by the growth inhibition test, and the synergistic effect was assessed by determination of the fractional inhibitory concentration index. Anti-Pa48 IgY shows antimicrobial activity at 1.25 mg/ml and anti-Pa23 IgY shows antimicrobial activity at 2.5 mg/ml. The fractional inhibitory concentration indices of anti-Pa48 IgY and ceftazidime, or imipenem, or meropenem at 72 h of experiment were 0.189, 0.209, and 0.440, respectively. For anti-Pa23 IgY, the fractional inhibitory concentration indices were 0.440 with ceftazidime, 0.453 with imipenem, and 0.441 with meropenem at 72 h. We conclude that there is a synergistic action between anti-P. aeruginosa IgY and the antimicrobials tested. Further studies are necessary to investigate the mechanisms associated with this action.
Topics: Animals; Anti-Bacterial Agents; Ceftazidime; Chickens; Female; Imipenem; Immunoglobulins; Meropenem; Microbial Sensitivity Tests; Pseudomonas Infections; Pseudomonas aeruginosa
PubMed: 35640520
DOI: 10.1016/j.molimm.2022.05.010 -
Future Microbiology Jan 2023Meropenem-vaborbactam and delafloxacin activities were not assessed against spp. (), complex () and (). A total of 106 , 57 and 100 were tested with gradient...
Meropenem-vaborbactam and delafloxacin activities were not assessed against spp. (), complex () and (). A total of 106 , 57 and 100 were tested with gradient diffusion test of meropenem-vaborbactam, delafloxacin and comparators. Meropenem-vaborbactam MIC were 4 μg/ml for , 1 μg/ml for , 2 μg/ml for and , and 32 μg/ml for . Delafloxacin MIC were 4 μg/ml for , 0.25 μg/ml for and , 2 μg/ml for , and 0.5 μg/m for . meropenem-vaborbactam MICs were fourfold lower than meropenem for 28.3% , 77.2% , 53.8% and 77.2% . Meropenem-vaborbactam and delafloxacin are active against and .
Topics: Meropenem; Anti-Bacterial Agents; Gram-Negative Bacteria; Stenotrophomonas maltophilia; Burkholderia cepacia complex; Microbial Sensitivity Tests
PubMed: 36722304
DOI: 10.2217/fmb-2021-0278 -
The Journal of Antimicrobial... Nov 2021To investigate the increase in the rates of OXA-48-like-producing isolates during 3 years of global surveillance.
OBJECTIVES
To investigate the increase in the rates of OXA-48-like-producing isolates during 3 years of global surveillance.
METHODS
Among 55?>162 Enterobacterales isolates, 354 carbapenem-resistant isolates carried genes encoding OXA-48-like enzymes. Isolates were susceptibility tested for ceftazidime/avibactam and comparators by broth microdilution methods. Analysis of β-lactam resistance mechanisms and MLST was performed in silico using WGS data.
RESULTS
OXA-48-like-producing isolates increased from 0.5% (94/18 656) in 2016 to 0.9% (169/18?>808) in 2018. OXA-48 was the most common variant; isolates primarily were Klebsiella pneumoniae (318/354 isolates) from Europe and adjacent countries. MLST analysis revealed a diversity of STs, but K. pneumoniae belonging to ST395, ST23 and ST11 were observed most frequently. Thirty-nine isolates harboured MBLs and were resistant to most agents tested. The presence of blaCTX-M-15 (258 isolates), OmpK35 nonsense mutations (232) and OmpK36 alterations (316) was common among OXA-48 producers. Ceftazidime, cefepime and aztreonam susceptibility rates, when applying CLSI breakpoints, were 12%-15% lower for isolates carrying ESBLs alone and with either or both OmpK35 stop codons and OmpK36 alterations. Meropenem and, remarkably, meropenem/vaborbactam were affected by specific OmpK36 alterations when a deleterious mutation also was observed in OmpK35. These mechanisms caused a decrease of 12%-42% in the susceptibility rates for meropenem and meropenem/vaborbactam. Ceftazidime/avibactam susceptibility rates were >98.9%, regardless of the presence of additional β-lactam resistance mechanisms.
CONCLUSIONS
Guidelines for the treatment of infections caused by OXA-48-producing isolates are scarce and, as the dissemination of these isolates continues, studies are needed to help physicians understand treatment options for these infections.
Topics: Anti-Bacterial Agents; Azabicyclo Compounds; Boronic Acids; Ceftazidime; Drug Combinations; Enterobacteriaceae; Heterocyclic Compounds, 1-Ring; Meropenem; Microbial Sensitivity Tests; Multilocus Sequence Typing; beta-Lactamases
PubMed: 34459890
DOI: 10.1093/jac/dkab306 -
Injury Aug 2022Cannulated screws are often used in the management of open lower extremity fractures. These fractures exhibit broad contamination profiles, necessitating empirical...
Concentrations of co-administered vancomycin and meropenem in the internal dead space of a cannulated screw and in cancellous bone adjacent to the screw - Evaluated by microdialysis in a porcine model.
BACKGROUND
Cannulated screws are often used in the management of open lower extremity fractures. These fractures exhibit broad contamination profiles, necessitating empirical Gram-positive and Gram-negative antibiotic coverage. To ensure full antibiotic protection of the cannulated screw and the bone tissue, it is generally accepted that target tissue antibiotic concentrations, as a minimum, reach and remain above relevant epidemiological cut-off minimal inhibitory concentrations (T>MIC) for a sufficient amount of time.
METHODS
8 female pigs were included. Microdialysis catheters were placed in the internal dead space of a cannulated screw placed in tibial cancellous bone, in tibial cancellous bone adjacent to the screw (mean distance to the screw: 3 mm), and in cancellous bone on the contralateral tibia. Following single-dose simultaneous intravenous administrations of vancomycin (1000 mg) and meropenem (1000 mg), microdialysates and plasma were dynamically sampled over 8 h. The applied MIC targets ranged from 1 to 4 µg/mL for vancomycin and 0.125-2 µg/mL for meropenem RESULTS: For both drugs, and for all MIC targets investigated (except for the high vancomycin target: 4 µg/mL), the internal dead space of the cannulated screw had the shortest T>MIC. At the low MIC targets T>MIC ranged between 88 and 449 min across sampling sites for vancomycin (1 µg/mL), and 148-406 min for meropenem (0.125 µg/mL). For the high MIC targets, T>MIC ranged between 3 and 446 min for vancomycin (4 μg/mL) and 17-181 min for meropenem (2 μg/mL). Vancomycin displayed longer T>MIC (2 and 4 μg/mL), higher area under the concentration time curve (AUC) and peak drug concentration in the proximal tibial cancellous bone without a screw nearby. For meropenem, only the cancellous bone AUC was significantly higher on the side with no screw.
CONCLUSION
We found short T>MIC, particularly for the high MIC targets for vancomycin and meropenem, both inside the cannulated screw and in cancellous bone adjacent to the screw. The presence of a cannulated screw impaired the penetration of especially vancomycin into cancellous bone adjacent to the screw. More aggressive or different vancomycin and meropenem approaches may be considered to encompass contaminating differences and to ensure a theoretically more sufficient antibiotic protection of cannulated screws when used in the management of open lower extremity fractures.
Topics: Animals; Anti-Bacterial Agents; Cancellous Bone; Female; Meropenem; Microdialysis; Swine; Vancomycin
PubMed: 35710595
DOI: 10.1016/j.injury.2022.06.008 -
Antimicrobial Agents and Chemotherapy Aug 2022Morbidity and mortality related to ventriculitis in neurocritical care patients remain high. Antibiotic dose optimization may improve therapeutic outcomes. In this...
Morbidity and mortality related to ventriculitis in neurocritical care patients remain high. Antibiotic dose optimization may improve therapeutic outcomes. In this study, a population pharmacokinetic model of meropenem in infected critically ill patients was developed. We applied the final model to determine optimal meropenem dosing regimens required to achieve targeted cerebrospinal fluid exposures. Neurocritical care patients receiving meropenem and with a diagnosis of ventriculitis or extracranial infection were recruited from two centers to this study. Serial plasma and cerebrospinal fluid samples were collected and assayed. Population pharmacokinetic modeling and Monte Carlo dosing simulations were performed using Pmetrics. We sought to determine optimized dosing regimens that achieved meropenem cerebrospinal fluid concentrations above pathogen MICs for 40% of the dosing interval, or a higher target ratio of meropenem cerebrospinal fluid trough concentrations to pathogen MIC of ≥1. In total, 53 plasma and 34 cerebrospinal fluid samples were obtained from eight patients. Meropenem pharmacokinetics were appropriately described using a three-compartment model with linear plasma clearance scaled for creatinine clearance and cerebrospinal fluid penetration scaled for patient age. Considerable interindividual pharmacokinetic variability was apparent, particularly in the cerebrospinal fluid. Percent coefficients of variation for meropenem clearance from plasma and cerebrospinal fluid were 41.7% and 89.6%, respectively; for meropenem, the volume of distribution in plasma and cerebrospinal fluid values were 63.4% and 58.3%, respectively. High doses (up to 8 to 10 g/day) improved attainment of meropenem cerebrospinal fluid target exposures, particularly for less susceptible organisms (MICs, ≥0.25 mg/L). Standard meropenem doses of 2 g every 8 h may not achieve effective concentrations in cerebrospinal fluid in all critically ill patients. Higher doses, or alternative dosing methods (e.g., loading dose followed by continuous infusion) may be required to optimize cerebrospinal fluid exposures. Doses of up to 8 to 10 g/day either as intermittent boluses or continuous infusion would be suitable for patients with augmented renal clearance; lower doses may be considered for patients with impaired renal function as empirical suggestions. Ongoing dosing should be tailored to the individual patient circumstances. Notably, the study population was small and dosing recommendations may not be generalizable to all critically ill patients.
Topics: Anti-Bacterial Agents; Cerebral Ventriculitis; Critical Illness; Humans; Meropenem; Prospective Studies; Renal Insufficiency; Thienamycins
PubMed: 35862757
DOI: 10.1128/aac.00142-22 -
The Journal of Antimicrobial... Dec 2022Molecular analysis of meropenem-resistant mechanisms in mutants emerging from long-term in vitro meropenem exposure to borderline meropenem-susceptible...
Full-length whole-genome sequencing analysis of emerged meropenem-resistant mutants during long-term in vitro exposure to meropenem for borderline meropenem-susceptible carbapenemase-producing and non-carbapenemase-producing Enterobacterales.
OBJECTIVES
Molecular analysis of meropenem-resistant mechanisms in mutants emerging from long-term in vitro meropenem exposure to borderline meropenem-susceptible carbapenemase-producing Enterobacterales (CPE) and non-CPE.
METHODS
Escherichia coli TUM13867 harbouring both blaIMP-6- and blaCTX-M-2-carrying IncN plasmid and Citrobacter koseri TUM13189 with blaCTX-M-2-carrying chromosome were used. Meropenem MIC was 1 mg/L against both strains. Each strain was cultured in the hollow-fibre infection model (HFIM) to approximately 1 × 106 colony formation unit (cfu)/mL, and meropenem 1 g q8h treatment was initiated. Then, changes in total and meropenem-resistant populations were observed for 124 h. Meropenem resistance mechanisms were analysed using full-length whole-genome sequencing (WGS), reverse-transcription quantitative PCR and digital PCR.
RESULTS
Meropenem reduced TUM13867 and TUM13189 to approximately 5 and 2 log10 cfu/mL, respectively, at 2 h after initiation, but regrowth was observed at 24 h. The meropenem-resistant mutant emergence frequency at 120 and 124 h was 4.4 × 10-4 for TUM13867 and 7.6 × 10-1 for TUM13189. Meropenem MIC of the mutants derived from TUM13867 (TUM20902) and TUM13189 (TUM20903) increased 4- and 16-fold, respectively. TUM20902, which harboured pMTY20902_IncN plasmid with a 27 505-bp deletion that included blaCTX-M-2, and blaIMP-6 showed 4.21-fold higher levels of transcription than the parental strain. TUM20903 had a 49 316-bp deletion that included ompC and a replicative increase of blaCTX-M-2 to three copies.
CONCLUSIONS
Molecular analysis including full-length WGS revealed that the resistance mechanisms of meropenem-resistant mutants that emerged during long-term in vitro meropenem exposure were increased blaIMP-6 transcripts in CPE and increased blaCTX-M-2 transcripts due to gene triplication and OmpC loss resulting from ompC deletion in non-CPE.
Topics: Meropenem; Anti-Bacterial Agents; Microbial Sensitivity Tests; Bacterial Proteins; beta-Lactamases; Escherichia coli; Plasmids
PubMed: 36374518
DOI: 10.1093/jac/dkac376