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PloS One 2020β-Lactam antibiotic detection has significant implications in food safety control, environmental monitoring and pharmacokinetics study. Here, we report the development...
β-Lactam antibiotic detection has significant implications in food safety control, environmental monitoring and pharmacokinetics study. Here, we report the development of two BADAN-conjugated β-lactamases, E166Cb and E166Cb/N170Q, as sensitive biosensors for β-lactam antibiotic detection. These biosensors were constructed by coupling an environment-sensitive BADAN probe onto location 166 at the active site of the PenP β-lactamase E166C and E166C/N170Q mutants. They gave fluorescence turn-on signals in response to β-lactam antibiotics. Molecular dynamics simulation of E166Cb suggested that the turn-on signal might be attributed to a polarity change of the microenvironment of BADAN and the removal of the fluorescence quenching effect on BADAN exerted by a nearby Tyr-105 upon the antibiotic binding. In the detection of four β-lactams (penicillin G, penicillin V, cefotaxime and moxalactam), both E166Cb and E166Cb/N170Q delivered signal outputs in an antibiotic-concentration dependent manner with a dynamic range spanning from 10 nM to 1 μM. Compared to E166Cb, E166Cb/N170Q generally exhibited more stable signals owing to its higher deficiency in hydrolyzing the antibiotic analyte. The overall biosensor performance of E166Cb and E166Cb/N170Q was comparable to that of their respective fluorescein-modified counterparts, E166Cf and E166Cf/N170Q. But comparatively, the BADAN-conjugated enzymes showed a higher sensitivity, displayed a faster response in detecting moxalactam and a more stable fluorescence signals towards penicillin G. This study illustrates the potential of BADAN-conjugated β-lactamases as biosensing devices for β-lactam antibiotics.
Topics: 2-Naphthylamine; Anti-Bacterial Agents; Biosensing Techniques; Enzymes, Immobilized; Molecular Dynamics Simulation; beta-Lactamases; beta-Lactams
PubMed: 33125437
DOI: 10.1371/journal.pone.0241594 -
Journal of Clinical Pharmacy and... Feb 2021We present two cases of severe coagulation disorders induced by latamoxef, thereby revealing risk factors of coagulation disorder in latamoxef-treated patients.
WHAT IS KNOWN AND OBJECTIVE
We present two cases of severe coagulation disorders induced by latamoxef, thereby revealing risk factors of coagulation disorder in latamoxef-treated patients.
CASE SUMMARY
Two very elderly patients developed haemorrhage, and coagulation tests showed a longer prothrombin time (PT), activated partial thromboplastin time (APTT) and a high international normalized ratio (INR). Latamoxef was thought to be responsible for the coagulopathy in these patients, and coagulation disorder was relieved after vitamin-K intake.
WHAT IS NEW AND CONCLUSION
We report on two cases of coagulopathy in patients given latamoxef. Advanced age, deficiency in vitamin-K intake, poor nutritional status, abnormal coagulation history, ongoing anti-coagulation/anti-aggregation therapy, renal dysfunction and polypharmacy are possible contributory factors, and should be looked out for when prescribing latamoxef.
Topics: Aged, 80 and over; Anti-Bacterial Agents; Blood Coagulation Disorders; Blood Coagulation Tests; Diagnosis, Differential; Humans; International Normalized Ratio; Male; Moxalactam; Partial Thromboplastin Time; Pneumonia, Bacterial
PubMed: 32949406
DOI: 10.1111/jcpt.13266 -
Pharmacological Research Oct 2020Identification of risk factors for antibiotic treatment failure is urgently needed in acute exacerbations of chronic obstructive pulmonary disease (AECOPD). Here we... (Comparative Study)
Comparative Study
Identification of risk factors for antibiotic treatment failure is urgently needed in acute exacerbations of chronic obstructive pulmonary disease (AECOPD). Here we investigated the relationship between sputum microbiome and clinical outcome of choice of initial antibiotics during hospitalization of AECOPD patients. Sputum samples of 41 AECOPD patients and 26 healthy controls were collected from Guangzhou Medical University, China. Samples were processed for 16S rRNA gene-based microbiome profiling. Thirty patients recovered with initial antibiotic treatment (antibiotic success or AS), while 11 patients showed poor outcome (antibiotic failure or AF). Substantial differences in microbiome were observed in AF versus AS patients and healthy controls. There was significantly decreased alpha diversity and increased relative abundances of Pseudomonas, Achromobacter, Stenotrophomonas and Ralstonia in AF patients. Conversely, Prevotella, Peptostreptococcus, Leptotrichia and Selenomonas were depleted. The prevalence of Selenomonas was markedly reduced in AF versus AS patients (9.1 % versus 60.0 %, P = 0.004). The AF patients with similar microbiome profiles in general responded well to the same new antibiotics in the adjusted therapy, indicating sputum microbiome may help guide the adjustment of antibiotics. Random forest analysis identified five microbiome operational taxonomic units together with C-reactive protein, procalcitonin and blood neutrophil count showing best predictability for antibiotic treatment outcome (area under curve 0.885). Functional inference revealed an enrichment of microbial genes in xenobiotic metabolism and antimicrobial resistance in AF patients, whereas genes in DNA repair and amino acid metabolism were depleted. Sputum microbiome may determine the clinical outcome of initial antibiotic treatment and be considered in the risk management of antibiotics in AECOPD.
Topics: Aged; Anti-Bacterial Agents; Bacteria; Case-Control Studies; Disease Progression; Female; Hospitalization; Humans; Inpatients; Lung; Male; Microbial Sensitivity Tests; Microbiota; Middle Aged; Pilot Projects; Pulmonary Disease, Chronic Obstructive; Ribotyping; Sputum; Treatment Outcome
PubMed: 32730904
DOI: 10.1016/j.phrs.2020.105095 -
Emerging Microbes & Infections 2020(), especially methicillin-resistant (MRSA), is a major cause of pneumonia, resulting in severe morbidity and mortality in adults and children. Sortase A (SrtA), which...
(), especially methicillin-resistant (MRSA), is a major cause of pneumonia, resulting in severe morbidity and mortality in adults and children. Sortase A (SrtA), which mediates the anchoring of cell surface proteins in the cell wall, is an important virulence factor of . Here, we found that salvianolic acid A (Sal A), which is a natural product that does not affect the growth of , could inhibit SrtA activity (IC = 5.75 μg/ml) and repress the adhesion of bacteria to fibrinogen, the anchoring of protein A to cell wall, the biofilm formation, and the ability of to invade A549 cells. Furthermore, studies demonstrated that Sal A treatment reduced inflammation and protected mice against lethal pneumonia caused by MRSA. More significantly, full protection (a survival rate of 100%) was achieved when Sal A was administered in combination with latamoxef. Together, these results indicate that Sal A could be developed into a promising therapeutic drug to combat MRSA infections while limiting resistance development.
Topics: Aminoacyltransferases; Animals; Bacterial Proteins; Biofilms; Caffeic Acids; Cysteine Endopeptidases; Drug Synergism; Female; Humans; Lactates; Methicillin-Resistant Staphylococcus aureus; Mice; Mice, Inbred C57BL; Moxalactam; Pneumonia; Staphylococcal Infections
PubMed: 31969071
DOI: 10.1080/22221751.2020.1711817 -
Protein Science : a Publication of the... Mar 2020Emergence of Enterobacteriaceae harboring metallo-β-lactamases (MBL) has raised global threats due to their broad antibiotic resistance profiles and the lack of...
Structural and biochemical analysis of the metallo-β-lactamase L1 from emerging pathogen Stenotrophomonas maltophilia revealed the subtle but distinct di-metal scaffold for catalytic activity.
Emergence of Enterobacteriaceae harboring metallo-β-lactamases (MBL) has raised global threats due to their broad antibiotic resistance profiles and the lack of effective inhibitors against them. We have been studied one of the emerging environmental MBL, the L1 from Stenotrophomonas maltophilia K279a. We determined several crystal structures of L1 complexes with three different classes of β-lactam antibiotics (penicillin G, moxalactam, meropenem, and imipenem), with the inhibitor captopril and different metal ions (Zn , Cd , and Cu ). All hydrolyzed antibiotics and the inhibitor were found binding to two Zn ions mainly through the opened lactam ring and some hydrophobic interactions with the binding pocket atoms. Without a metal ion, the active site is very similarly maintained as that of the native form with two Zn ions, however, the protein does not bind the substrate moxalactam. When two Zn ions were replaced with other metal ions, the same di-metal scaffold was maintained and the added moxalactam was found hydrolyzed in the active site. Differential scanning fluorimetry and isothermal titration calorimetry were used to study thermodynamic properties of L1 MBL compared with New Deli Metallo-β-lactamase-1 (NDM-1). Both enzymes are significantly stabilized by Zn and other divalent metals but showed different dependency. These studies also suggest that moxalactam and its hydrolyzed form may bind and dissociate with different kinetic modes with or without Zn for each of L1 and NDM-1. Our analysis implicates metal ions, in forming a distinct di-metal scaffold, which is central to the enzyme stability, promiscuous substrate binding and versatile catalytic activity. STATEMENT: The L1 metallo-β-lactamase from an environmental multidrug-resistant opportunistic pathogen Stenotrophomonas maltophilia K279a has been studied by determining 3D structures of L1 enzyme in the complexes with several β-lactam antibiotics and different divalent metals and characterizing its biochemical and ligand binding properties. We found that the two-metal center in the active site is critical in the enzymatic process including antibiotics recognition and binding, which explains the enzyme's activity toward diverse antibiotic substrates. This study provides the critical information for understanding the ligand recognition and for advanced drug development.
Topics: Anti-Bacterial Agents; Binding Sites; Biocatalysis; Lactams; Metals, Heavy; Microbial Sensitivity Tests; Models, Molecular; Stenotrophomonas maltophilia; beta-Lactamase Inhibitors; beta-Lactamases
PubMed: 31846104
DOI: 10.1002/pro.3804 -
International Journal of Environmental... Oct 2019Cephalosporins that contain the N-methylthiotetrazole side chain (NMTT-cephalosporin) have been reported to be associated with coagulation-related adverse events;... (Meta-Analysis)
Meta-Analysis
Cephalosporins that contain the N-methylthiotetrazole side chain (NMTT-cephalosporin) have been reported to be associated with coagulation-related adverse events; however, a comprehensive evaluation regarding the association is lacking. A systematic review and meta-analysis were conducted to assess the safety profile of NMTT-cephalosporins with respect to hypoprothrombinemia and bleeding. The MEDLINE, Embase, Cochrane, and RISS databases were systematically searched for clinical studies up to October 2018. The association between NMTT-cephalosporins and hypoprothrombinemia was estimated using an odds ratio (OR) with a 95% confidence interval (CI). A total of 15 studies on cefamandole, cefoperazone, cefotetan, cefmetazole, and moxalactam were identified and included in the meta-analysis. Hypoprothrombinemia (OR 1.676, 95% CI 1.275-2.203) and prothrombin time (PT) prolongation (OR 2.050, 95% CI 1.398-3.005) were significantly associated with NMTT-cephalosporins, whereas bleeding was not (OR 1.359, 95% CI 0.920-2.009). Subgroup analyses revealed that cefoperazone (OR 2.506, 95% CI 1.293-4.860), cefamandole (OR 3.247, 95% CI 1.083-9.733), and moxalactam (OR 3.367, 95% CI 1.725-6.572) were significantly associated with hypoprothrombinemia. An Antimicrobial Stewardship Program led by a multidisciplinary team could play a critical role in monitoring cephalosporin-related hypoprothrombinemia or PT prolongation in patients with underlying clinical conditions at risk for bleeding. The multidisciplinary team could also assist in communicating the potential safety concerns regarding NMTT-cephalosporin use with healthcare professionals to decrease the risk of adverse events.
Topics: Anti-Bacterial Agents; Cephalosporins; Humans; Hypoprothrombinemias; Male
PubMed: 31623191
DOI: 10.3390/ijerph16203937 -
Journal of Medicinal Chemistry Nov 2019Small-molecule aggregates are a leading cause of artifacts in early drug discovery, but little is known about their interactions with proteins, nor why some proteins are...
Small-molecule aggregates are a leading cause of artifacts in early drug discovery, but little is known about their interactions with proteins, nor why some proteins are more susceptible to inhibition than others. A possible reason for this apparent selectivity is that aggregation-based inhibition, as a stoichiometric process, is sensitive to protein concentration, which varies across assays. Alternatively, local protein unfolding by aggregates may lead to selectivity since stability varies among proteins. To deconvolute these effects, we used differentially stable point mutants of a single protein, TEM-1 β-lactamase. Broadly, destabilized mutants had higher affinities for and were more potently inhibited by aggregates versus more stable variants. The addition of the irreversible inhibitor moxalactam destabilized several mutants, and these typically bound tighter to a colloidal particle, while the only mutant it stabilized bound weaker. These results suggest that less-stable enzymes are more easily sequestered and inhibited by colloidal aggregates.
Topics: Enzyme Inhibitors; Mutation; Protein Stability; Thermodynamics; beta-Lactamases
PubMed: 31589047
DOI: 10.1021/acs.jmedchem.9b01019 -
Journal of Pharmaceutical and... Oct 2019A simple and sensitive method was developed for separation and characterization of seventeen impurities from commercial latamoxef sodium for injection by liquid...
A simple and sensitive method was developed for separation and characterization of seventeen impurities from commercial latamoxef sodium for injection by liquid chromatography combined with electrospray ionization and QTOF mass spectrometer (LC-ESI-QTOF MS). The chromatographic separation was performed on a Boston Green ODS-AQ C18 column (250 mm × 4.6 mm, 5 μm) under gradient mode using binary mobile phase: (A) ammonium acetate (10 mM)-methanol (99:1, v/v) and (B) ammonium acetate (10 mM)-methanol (70:30, v/v). Based on tandem multistage MS and high resolution MS data, the molecular formulas and structures of unknown impurities were inferred. A plausible formation mechanism of impurities was also proposed. In addition, the fragmentation regularity of degraded impurities in positive-ion mode was summarized.
Topics: Acetates; Chromatography, Liquid; Drug Contamination; Ions; Methanol; Moxalactam; Sodium; Spectrometry, Mass, Electrospray Ionization
PubMed: 31377652
DOI: 10.1016/j.jpba.2019.112793