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Analytical Chemistry Aug 2023The global prevalence of β-lactam allergy poses a major challenge in administering first-line antibiotics, such as penicillins, to a significant portion of the...
The global prevalence of β-lactam allergy poses a major challenge in administering first-line antibiotics, such as penicillins, to a significant portion of the population. The lack of β-lactam IgE antibody pools with defined selectivity hampers the standardization and validation of in vitro assays for β-lactam allergy testing. To address this limitation, this study introduces a synthetic IgE specific to β-lactam antibiotics as a valuable tool for drug allergy research and diagnostic tests. Using phage display technology, we constructed a library of human single-chain antibody fragments (scFv) to target the primary determinant of amoxicillin, a widely used β-lactam antibiotic. Subsequently, we produced a complete human synthetic IgE molecule using the highly efficient baculovirus expression vector system. This synthetic IgE molecule served as a standard in an in vitro chemiluminescence immunoassay for β-lactam antibiotic allergy testing. Our results demonstrated a detection limit of 0.05 IU/mL (0.63 pM), excellent specificity (100%), and a four-fold higher clinical sensitivity (73%) compared to the in vitro reference assay when testing a cohort of 150 serum samples. These findings have significant implications for reliable interlaboratory comparison studies, accurate labeling of allergic patients, and combating the global public health threat of antimicrobial resistance. Furthermore, by serving as a valuable trueness control material, the synthetic IgE facilitates the standardization of diagnostic tests for β-lactam allergy and demonstrates the potential of utilizing this synthetic strategy as a promising approach for generating reference materials in drug allergy research and diagnostics.
Topics: Humans; Skin Tests; Anti-Bacterial Agents; beta-Lactams; Penicillins; Drug Hypersensitivity; Monobactams; beta Lactam Antibiotics; Hypersensitivity; Immunoglobulin E
PubMed: 37545056
DOI: 10.1021/acs.analchem.3c02284 -
Annals of Clinical Microbiology and... Aug 2023The aim of this study was to assess the risk factors for colistin-resistant carbapenemase-producing Enterobacterales (CR-CPE), and describe the mortality associated with...
PURPOSE
The aim of this study was to assess the risk factors for colistin-resistant carbapenemase-producing Enterobacterales (CR-CPE), and describe the mortality associated with this organism, in a low-income country.
METHODS
A descriptive, observational, and prospective multicenter study was carried out in Guayaquil, Ecuador. All patients with carbapenem-resistant Enterobacterales admitted between December 2021 and May 2022 were enrolled. Infection definitions were established according to the Centers for Disease Control and Prevention (CDC) protocols. The presence of carbapenemase-producing Enterobacterales was confirmed with a multiplex PCR for bla bla bla bla and bla genes. MCR-1 production was studied molecularly, and MLST assays were carried out.
RESULTS
Out of 114 patients enrolled in the study, 32 (28.07%) had at least one positive sample for CR-CPE. Klebsiella pneumoniae ST512-KPC-3 was the most frequent microorganism isolated. Parenteral feeding, β-lactamase inhibitor use, recent hemodialysis, and renal failure were all considered independent risk factors for carrying CR-CPE. A mortality of 41.22% was detected, but we could not find any difference between colistin-resistant and colistin-susceptible CPE. MCR-1 production was not detected in any of the isolates studied.
CONCLUSION
A significant burden for CR-CPE was found in a South American country that was mainly caused by the high-risk clone K. pneumoniae ST512-KPC-3 and not mediated by mcr-1 production. Its acquisition involved parenteral feeding, β-lactamase inhibitor use, recent hemodialysis, and renal failure as independent risk factors, demonstrating the critical need for infection prevention and stewardship programs to avoid dissemination to other countries in the region.
Topics: Humans; Colistin; beta-Lactamase Inhibitors; Multilocus Sequence Typing; Prospective Studies; Bacterial Proteins; beta-Lactamases; Klebsiella pneumoniae; Monobactams; Risk Factors; Microbial Sensitivity Tests; Anti-Bacterial Agents
PubMed: 37533063
DOI: 10.1186/s12941-023-00609-8 -
European Journal of Clinical... Sep 2023This study aimed to report reference method antimicrobial susceptibility results for 24,937 recent (2019-2021) clinical isolates of Enterobacterales from 27 countries in...
In vitro activity of aztreonam-avibactam against Enterobacterales isolates collected in Latin America, Africa/Middle East, Asia, and Eurasia for the ATLAS Global Surveillance Program in 2019-2021.
This study aimed to report reference method antimicrobial susceptibility results for 24,937 recent (2019-2021) clinical isolates of Enterobacterales from 27 countries in Latin America, Eurasia, Africa/Middle East, and Asia with a focus on the investigational combination aztreonam-avibactam against metallo-β-lactamase (MBL) isolates. Antimicrobial susceptibility testing was performed by the CLSI broth microdilution methodology. Minimum inhibitory concentrations (MICs) were interpreted using the CLSI (2022) breakpoints for all agents except aztreonam-avibactam (provisional pharmacokinetic/pharmacodynamic susceptible breakpoint, ≤ 8 mg/L) and tigecycline (US-FDA). Molecular testing for β-lactamase genes was performed on isolates with meropenem MICs ≥ 2 mg/L, ceftazidime-avibactam MICs ≥ 16 mg/L, and/or aztreonam-avibactam MICs ≥ 16 mg/L, and 50% of isolates of Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Klebsiella variicola, and Proteus mirabilis testing with ceftazidime and/or aztreonam MICs ≥ 2 mg/L. Aztreonam-avibactam inhibited 99.8% of all Enterobacterales at ≤ 8 mg/L (MIC, 0.25 mg/L) and maintained activity against phenotypically resistant subsets of multidrug-resistant (MDR) (99.5% susceptible), extensively drug-resistant (XDR) (98.7%), and carbapenem-resistant Enterobacterales (CRE) (99.1%) isolates. At ≤ 8 mg/L, aztreonam-avibactam inhibited 100%, 99.6%, 99.6%, and 98.8% of KPC-, OXA-48-like-, ESBL-, and MBL-carrying isolates, respectively. MBL-positive isolates were most prevalent in India (20.5%), Guatemala (13.8%), and Jordan (13.2%). No differences in the activity of aztreonam-avibactam were observed across the global regions evaluated. At a concentration of ≤ 8 mg/L, aztreonam-avibactam inhibited almost all Enterobacterales collected from developing countries, including MBL-producing isolates. The widespread dissemination of MBLs among Enterobacterales highlights the unmet need for new agents such as aztreonam-avibactam for the treatment of CRE infections.
Topics: Humans; Aztreonam; Anti-Bacterial Agents; Latin America; Enterobacteriaceae; Ceftazidime; beta-Lactamases; Asia; Middle East; Carbapenems; Drug Combinations; Microbial Sensitivity Tests
PubMed: 37526796
DOI: 10.1007/s10096-023-04645-2 -
Acta Pharmaceutica Sinica. B Jul 2023A series of new monobactam sulfonates is continuously synthesized and evaluated for their antimicrobial efficacies against Gram-negative bacteria. Compound (IMBZ18G) is...
A series of new monobactam sulfonates is continuously synthesized and evaluated for their antimicrobial efficacies against Gram-negative bacteria. Compound (IMBZ18G) is highly effective and against clinically intractable multi-drug-resistant (MDR) Gram-negative strains, with a highly druglike nature. The checkerboard assay reveals its significant synergistic effect with -lactamase inhibitor avibactam, and the MIC values against MDR were reduced up to 4-512 folds X-ray co-crystal and chemoproteomic assays indicate that the anti-MDR bacteria effect of results from the dual inhibition of the common PBP3 and some class A and C -lactamases. Accordingly, preclinical studies of alone and ‒avibactam combination as potential innovative candidates are actively going on, in the treatment of -lactamase-producing MDR Gram-negative bacterial infections.
PubMed: 37521870
DOI: 10.1016/j.apsb.2023.03.002 -
PLoS Pathogens Jul 2023Central metabolic pathways control virulence and antibiotic resistance, and constitute potential targets for antibacterial drugs. In Staphylococcus aureus the role of...
Central metabolic pathways control virulence and antibiotic resistance, and constitute potential targets for antibacterial drugs. In Staphylococcus aureus the role of the pentose phosphate pathway (PPP) remains largely unexplored. Mutation of the 6-phosphogluconolactonase gene pgl, which encodes the only non-essential enzyme in the oxidative phase of the PPP, significantly increased MRSA resistance to β-lactam antibiotics, particularly in chemically defined media with physiologically-relevant concentrations of glucose, and reduced oxacillin (OX)-induced lysis. Expression of the methicillin-resistance penicillin binding protein 2a and peptidoglycan architecture were unaffected. Carbon tracing and metabolomics revealed extensive metabolic reprogramming in the pgl mutant including increased flux to glycolysis, the TCA cycle, and several cell envelope precursors, which was consistent with increased β-lactam resistance. Morphologically, pgl mutant cells were smaller than wild-type with a thicker cell wall and ruffled surface when grown in OX. The pgl mutation reduced resistance to Congo Red, sulfamethoxazole and oxidative stress, and increased resistance to targocil, fosfomycin and vancomycin. Levels of lipoteichoic acids (LTAs) were significantly reduced in pgl, which may limit cell lysis, while the surface charge of pgl cells was significantly more positive. A vraG mutation in pgl reversed the increased OX resistance phenotype, and partially restored wild-type surface charge, but not LTA levels. Mutations in vraF or graRS from the VraFG/GraRS complex that regulates DltABCD-mediated d-alanylation of teichoic acids (which in turn controls β-lactam resistance and surface charge), also restored wild-type OX susceptibility. Collectively these data show that reduced levels of LTAs and OX-induced lysis combined with a VraFG/GraRS-dependent increase in cell surface positive charge are accompanied by significantly increased OX resistance in an MRSA pgl mutant.
Topics: Methicillin-Resistant Staphylococcus aureus; Pentose Phosphate Pathway; Anti-Bacterial Agents; Oxacillin; Cell Wall; Monobactams; beta-Lactam Resistance; Bacterial Proteins; Microbial Sensitivity Tests
PubMed: 37486930
DOI: 10.1371/journal.ppat.1011536 -
BMC Cancer Jul 2023Tigecycline has a broad spectrum of antimicrobial activity and has been approved for the treatment of complicated intra-abdominal infections. However, it is debatable...
BACKGROUNDS
Tigecycline has a broad spectrum of antimicrobial activity and has been approved for the treatment of complicated intra-abdominal infections. However, it is debatable whether tigecycline should be used alone or in combination. This study aimed to investigate whether tigecycline plus β-lactam antibiotics (combination therapy [CT] group) are superior to tigecycline alone (monotherapy [MT] group) in non-critically ill intra-abdominal infection patients after tumor surgery.
METHODS
This was a multicenter, retrospective cohort study. The primary outcome was mortality during the hospital stay. Secondary outcomes were clinical success rate, microbial eradication rate, relapse rate within one week, course of treatment, and adverse effects. Propensity score matching (PSM) was used to adjust the degree of infection before medication between the MT and CT groups. Univariate comparisons were performed using the chi-squared test for qualitative variables and Student's t-test or the Mann-Whitney U-test for continuous variables, as appropriate. Multivariate logistic regression analysis was performed to examine the relationship between antimicrobial treatments and mortality during hospitalization. The paired samples Wilcoxon test was used to compare the parameters before and after medication.
RESULTS
In total, 291 patients were included in the final analysis: 128 in MT group and 163 in CT group. Mortality rate was 6.25% in the MT group and 6.13% in the CT group (P = 0.97). Multivariate logistic regression model showed that carbapenem-resistant organisms (OR: 4.35, 95% CI: 2.36 ~ 61.70) and age > 65 (OR: 1.32, 95% CI:1.19 ~ 3.01) were independent risk factors for death. CT group had a shorter defervescence time (P < 0.05), with less likelihood of relapse (P < 0.05) but had a more significant effect on activated partial thromboplastin and prothrombin time.
CONCLUSIONS
Tigecycline plus β-lactam wasn't superior to tigecycline monotherapy for the treatment of non-critically ill patients with intra-abdominal infection. But for advanced age patients with cancer, tigecycline combination therapy maybe a better choice in terms of mortality.
Topics: Humans; Tigecycline; Anti-Bacterial Agents; Retrospective Studies; Neoplasm Recurrence, Local; Intraabdominal Infections; Carbapenems; Monobactams; Anti-Infective Agents; Treatment Outcome
PubMed: 37474892
DOI: 10.1186/s12885-023-11169-7 -
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 -
Nature Communications Jul 2023Penicillin-binding proteins (PBPs) are essential for the formation of the bacterial cell wall. They are also the targets of β-lactam antibiotics. In Enterococcus...
Penicillin-binding proteins (PBPs) are essential for the formation of the bacterial cell wall. They are also the targets of β-lactam antibiotics. In Enterococcus faecium, high levels of resistance to β-lactams are associated with the expression of PBP5, with higher levels of resistance associated with distinct PBP5 variants. To define the molecular mechanism of PBP5-mediated resistance we leveraged biomolecular NMR spectroscopy of PBP5 - due to its size (>70 kDa) a challenging NMR target. Our data show that resistant PBP5 variants show significantly increased dynamics either alone or upon formation of the acyl-enzyme inhibitor complex. Furthermore, these variants also exhibit increased acyl-enzyme hydrolysis. Thus, reducing sidechain bulkiness and expanding surface loops results in increased dynamics that facilitates acyl-enzyme hydrolysis and, via increased β-lactam antibiotic turnover, facilitates β-lactam resistance. Together, these data provide the molecular basis of resistance of clinical E. faecium PBP5 variants, results that are likely applicable to the PBP family.
Topics: Penicillin-Binding Proteins; Anti-Bacterial Agents; Bacterial Proteins; beta-Lactam Resistance; Monobactams; beta-Lactams; Microbial Sensitivity Tests; Hexosyltransferases
PubMed: 37460557
DOI: 10.1038/s41467-023-39966-5 -
Frontiers in Cellular and Infection... 2023To evaluate the efficacy of ceftazidime-avibactam (CZA) and aztreonam-avibactam (AZA) against bloodstream infections (BSIs) or lower respiratory tract infections (LRTIs)...
Optimal treatment of ceftazidime-avibactam and aztreonam-avibactam against bloodstream infections or lower respiratory tract infections caused by extensively drug-resistant or pan drug-resistant (XDR/PDR) .
OBJECTIVE
To evaluate the efficacy of ceftazidime-avibactam (CZA) and aztreonam-avibactam (AZA) against bloodstream infections (BSIs) or lower respiratory tract infections (LRTIs) - caused by extensive drug-resistant or pan drug-resistant (XDR/PDR)
METHOD
The two-fold dilution method was used to determine the minimum inhibitory concentrations (MICs) of CZA/AZA against XDR/PDR . Whole-genome sequencing was used to analyze the resistance determinants of each isolate. Monte Carlo simulations (MCSs) were used to evaluate the probability of target attainment (PTA) and the cumulative fraction of response (CFR) of each CZA/AZA dosing regimen traditional infusion (TI)/optimized two-step-administration therapy (OTAT).
RESULTS
We found that XDR/PDR P. aeruginosa may carry some rare MBLs (e.g.: IND-6, SLB-1, THIN-B). isolates producing IMP-45, VIM-1, or VIM-2 were inhibited by AZA at a concentration of 2 to 8 mg/L. All isolates producing IND-6 plus other serine β-lactamases were high-level resistant to CZA/AZA (MICs >64 mg/L). All simulated dosing regimens of CZA/AZA against BSIs-causing XDR/PDR achieved 100% PTA when the MIC was ≤32 mg/L.
CONCLUSION
AZA has been considered as an option for the treatment of infections caused by XDR/PDR producing IMP-45, VIM-1, or VIM-2. OTAT with sufficient pharmacodynamic exposure may be an optimal treatment option for XDR/PDR with a high-level MIC of CZA/AZA.
Topics: Humans; Aztreonam; Anti-Bacterial Agents; Pseudomonas aeruginosa; Pharmaceutical Preparations; Drug Combinations; Respiratory Tract Infections; Sepsis; beta-Lactamases; Microbial Sensitivity Tests; Pseudomonas Infections
PubMed: 37457958
DOI: 10.3389/fcimb.2023.1023948 -
Journal of Cystic Fibrosis : Official... Jan 2024Antibiotic eradication therapies recommended for newly isolated Pseudomonas aeruginosa (Pa) in people with cystic fibrosis (pwCF) can be burdensome. ALPINE2 compared the... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Antibiotic eradication therapies recommended for newly isolated Pseudomonas aeruginosa (Pa) in people with cystic fibrosis (pwCF) can be burdensome. ALPINE2 compared the efficacy and safety of a shortened 14-day course of aztreonam for inhalation solution (AZLI) with 28-day AZLI in paediatric pwCF.
METHODS
ALPINE2 (a double-blind, phase 3b study) included children aged 3 months to <18 years with CF and new-onset Pa infection. Participants were randomized to receive 75 mg AZLI three times daily for either 28 or 14 days followed by 14 days' matched placebo. The primary endpoint was rate of primary Pa eradication (no Pa detected during the 4 weeks post AZLI treatment). Non-inferiority was achieved if the lower 95% CI bound of the treatment difference between the two arms was above -20%. Secondary endpoints included assessments of Pa recurrence during 108 weeks of follow-up after primary eradication. Safety endpoints included treatment-emergent adverse events (TEAEs).
RESULTS
In total, 149 participants were randomized (14-day AZLI, n = 74; 28-day AZLI, n = 75) and 142 (95.3%) completed treatment. Median age: 6.0 years (range: 0.3-17.0). Baseline characteristics were similar between treatment arms. Primary Pa eradication rates: 14-day AZLI, 55.9%; 28-day AZLI, 63.4%; treatment difference (CI), -8.0% (-24.6, 8.6%). Pa recurrence rates at follow-up end: 14-day AZLI, 54.1% (n = 20/37); 28-day AZLI, 41.9% (n = 18/43). TEAEs were similar between treatment arms. No new safety signals were observed.
CONCLUSIONS
Non-inferiority of 14-day AZLI versus 28-day AZLI was not demonstrated. Both courses were well tolerated, further supporting AZLI short-term safety in paediatric and adolescent pwCF.
CLINICALTRIALS
GOV: NCT03219164.
Topics: Adolescent; Humans; Child; Aztreonam; Pseudomonas aeruginosa; Cystic Fibrosis; Administration, Inhalation; Anti-Bacterial Agents; Pseudomonas Infections; Treatment Outcome
PubMed: 37455237
DOI: 10.1016/j.jcf.2023.06.008