-
Bioscience, Biotechnology, and... Apr 2019In this report, an artificial antigen (PFLX-BSA: Pefloxacin connected bovine serum albumin) was successfully prepared. The monoclonal antibody against pefloxacin was...
In this report, an artificial antigen (PFLX-BSA: Pefloxacin connected bovine serum albumin) was successfully prepared. The monoclonal antibody against pefloxacin was produced and characterized using a direct competitive ELISA. The linear range of detection was 0.115-6.564 µg/L. The limit of detection defined as IC was 0.170 ± 0.05 µg/L and the IC was 0.902 ± 0.03 µg/L. The antibody variable region genes were amplified, assembled, and sequenced. A three-dimensional structural model of the variable region was constructed to study the mechanism of antibody recognition using molecular docking analysis. Three predicted essential amino acids, Thr53, Arg97 of heavy chain and Thr52 of light chain, were mutated to verify the theoretical model. Three mutants lost binding activity significantly against pefloxacin as predicted. These may provide useful insights for studying antigen-antibody interaction mechanisms to improve antibody affinity maturation in vitro.
Topics: Animals; Anti-Bacterial Agents; Antibodies, Monoclonal; Antibody Affinity; Antibody Specificity; Binding Sites; Binding, Competitive; Cloning, Molecular; Enzyme-Linked Immunosorbent Assay; Escherichia coli; Gene Expression; Hybridomas; Immunization; Immunoconjugates; Immunoglobulin Variable Region; Limit of Detection; Mice; Mice, Inbred BALB C; Molecular Docking Simulation; Mutation; Pefloxacin; Protein Binding; Protein Structure, Secondary; Recombinant Proteins; Serum Albumin, Bovine; Structural Homology, Protein
PubMed: 30618329
DOI: 10.1080/09168451.2018.1562876 -
European Journal of Clinical... Sep 2019Recent studies show that rectal colonization with low-level ciprofloxacin-resistant Escherichia coli (ciprofloxacin minimal inhibitory concentration (MIC) above the...
Recent studies show that rectal colonization with low-level ciprofloxacin-resistant Escherichia coli (ciprofloxacin minimal inhibitory concentration (MIC) above the epidemiological cutoff point, but below the clinical breakpoint for resistance), i.e., in the range > 0.06-0.5 mg/L is an independent risk factor for febrile urinary tract infection after transrectal ultrasound-guided biopsy (TRUS-B) of the prostate, adding to the other risk posed by established ciprofloxacin resistance in E. coli (MIC > 0.5 mg/L) as currently defined. We aimed to identify the quinolone that by disk diffusion best discriminates phenotypic wild-type isolates (ciprofloxacin MIC ≤ 0.06 mg/L) of E. coli from isolates with acquired resistance, and to determine the resistance genotype of each isolate. The susceptibility of 108 E. coli isolates was evaluated by ciprofloxacin, levofloxacin, moxifloxacin, nalidixic acid, and pefloxacin disk diffusion and correlated to ciprofloxacin MIC (broth microdilution) using EUCAST methodology. Genotypic resistance was identified by PCR and DNA sequencing. The specificity was 100% for all quinolone disks. Sensitivity varied substantially, as follows: ciprofloxacin 59%, levofloxacin 46%, moxifloxacin 59%, nalidixic acid 97%, and pefloxacin 97%. We suggest that in situations where low-level quinolone resistance might be of importance, such as when screening for quinolone resistance in fecal samples pre-TRUS-B, a pefloxacin (S ≥ 24 mm) or nalidixic acid (S ≥ 19 mm) disk, or a combination of the two, should be used. In a setting where plasmid-mediated resistance is prevalent, pefloxacin might perform better than nalidixic acid.
Topics: Anti-Bacterial Agents; Drug Resistance, Bacterial; Escherichia coli; Humans; Microbial Sensitivity Tests; Phenotype; Quinolones; Sensitivity and Specificity; Urinary Tract Infections
PubMed: 31214796
DOI: 10.1007/s10096-019-03608-w -
Micromachines Apr 2023g-CN and g-CN/TCNQ composites with different doping levels were prepared using the copolymerization thermal method with melamine as a precursor. XRD, FT-IR, SEM, TEM,...
g-CN and g-CN/TCNQ composites with different doping levels were prepared using the copolymerization thermal method with melamine as a precursor. XRD, FT-IR, SEM, TEM, DRS, PL, and I-T characterized them. The composites were successfully prepared in this study. The photocatalytic degradation of pefloxacin (PEF), enrofloxacin (ciprofloxacin), and ciprofloxacin (ciprofloxacin) under visible light (λ > 550 nm) showed that the composite material had the best degradation effect on PEF. When TCNQ doping is 20 mg and catalyst dosage is 50 mg, the catalytic effect is the best, and the degradation rate reaches 91.6%, k = 0.0111 min, which is four times that of g-CN. Repeated experiments found that the cyclic stability of the g-CN/TCNQ composite was good. The XRD images were almost unchanged after five reactions. The radical capture experiments revealed that ·O was the main active species in the g-CN/TCNQ catalytic system, and h also played a role in PEF degradation. And the possible mechanism for PEF degradation was speculated.
PubMed: 37241565
DOI: 10.3390/mi14050941 -
Microbial Drug Resistance (Larchmont,... Jun 2019or group B (GBS) is an important pathogen in neonates and nonpregnant individuals. Epidemiological studies of GBS resistance to fluoroquinolones (FQs) in Latin...
or group B (GBS) is an important pathogen in neonates and nonpregnant individuals. Epidemiological studies of GBS resistance to fluoroquinolones (FQs) in Latin America are scarce. This study aimed to determine the local prevalence of FQ resistance in the frame of a national, prospective multicenter study of invasive GBS infections and to investigate mechanisms of resistance, serotype distribution, and clonal relationships among resistant isolates. From July 2014 to July 2015, 162 invasive GBS isolates were collected from 86 health care centers in 32 Argentinean cities. All isolates were screened for FQ nonsusceptibility using a five-disc scheme: levofloxacin (LVX), ciprofloxacin, norfloxacin (NOR), ofloxacin, and pefloxacin (PF). LVX minimal inhibitory concentration (MIC) was determined by the agar dilution method. Sequencing of internal regions of and genes was performed. Capsular typing and genetic characterization of nonsusceptible isolates were assessed by latex agglutination, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing. Twenty-four of one hundred sixty-two GBS isolates exhibited no inhibition zones to all tested FQs with an MIC range of 16-32 mg/L for LVX, and one isolate with MIC = 1 mg/L showed no inhibition zones around NOR and PF discs. In all resistant isolates, point mutations were detected in both genes. Serotype Ib was prevalent (88%). One PFGE type accounted for 84% of the FQ-resistant isolates and belonged to serotype Ib, sequence type 10. The prevalence of FQ resistance was 14.8% likely to be associated with dissemination of an ST10/serotype Ib clone. The unexpected high rate of resistance emphasizes the relevance for continuous surveillance of GBS epidemiology and antibiotic susceptibility.
Topics: Anti-Bacterial Agents; Argentina; Ciprofloxacin; DNA Gyrase; DNA Topoisomerase IV; Drug Resistance, Bacterial; Electrophoresis, Gel, Pulsed-Field; Epidemiological Monitoring; Gene Expression; Humans; Levofloxacin; Multilocus Sequence Typing; Norfloxacin; Ofloxacin; Pefloxacin; Point Mutation; Prevalence; Prospective Studies; Streptococcal Infections; Streptococcus agalactiae
PubMed: 30676886
DOI: 10.1089/mdr.2018.0246 -
European Journal of Medicinal Chemistry Feb 2020Amongst the fluoroquinolone antibacterials, the 7-piperazinyl containing chemotypes such as norfloxacin, enoxacin, ciprofloxacin, pefloxacin, lomefloxacin, enrofloxacin,... (Review)
Review
Amongst the fluoroquinolone antibacterials, the 7-piperazinyl containing chemotypes such as norfloxacin, enoxacin, ciprofloxacin, pefloxacin, lomefloxacin, enrofloxacin, ofloxacin, levofloxacin, gatifloxacin and sparfloxacin have been shown to possess non-classical activities including cytotoxicity against different cancer cell lines, induction of apoptosis, and cell cycle arrest at the S/G2 stage. Additionally, piperazinylquinolones (PQs) have enough flexibility for chemical modification via their N-4 of piperazine ring and carboxylic acid at C-3. Therefore, PQs have been considered as a starting point for design and development of new anticancer agents. This review has focused on the recent synthetic modifications of PQs which led to N-substituted and/or C-3 modified PQs with potential anticancer activity.
Topics: Animals; Anti-Bacterial Agents; Antineoplastic Agents; Bacteria; Cell Proliferation; Drug Screening Assays, Antitumor; Humans; Microbial Sensitivity Tests; Piperazines; Quinolones
PubMed: 31881454
DOI: 10.1016/j.ejmech.2019.111970 -
Talanta Mar 2023This paper describes the use of cyclodextrins (CDs) to improve the determination of fluoroquinolone antibiotics in human body fluids using surface-enhanced Raman...
This paper describes the use of cyclodextrins (CDs) to improve the determination of fluoroquinolone antibiotics in human body fluids using surface-enhanced Raman spectroscopy (SERS). CDs were used to (i) prepare the CD-SERS substrate (synthesis and stabilization of silver nanoparticles), (ii) increase the sensitivity of the assay by enhancing the interaction between analyte molecules and the substrate, and (iii) improve the analysis accuracy by reducing the interaction between the substrate and endogenous components of body fluids. Two native CDs (α-CD and β-CD) and two of their derivatives with hydroxypropyl groups were tested, and the best results were obtained with CD-SERS substrate prepared using native β-CD. The CD-SERS assay has been developed and optimized for the determination of commonly used and structurally related fluoroquinolones (ciprofloxacin, norfloxacin, pefloxacin, and levofloxacin) in urine and blood plasma samples. Importantly, the non-significant difference in the interaction of the CD-modified SERS substrate with various fluoroquinolones has been successfully used to develop a versatile assay suitable for the analyte-class-specific analysis. Calibration plots were obtained for concentration ranges suitable for the determination of the antibiotics in urine (50-500 μg mL) and blood plasma (1-6 μg mL). The following figures of merit were obtained (for urine and blood plasma, respectively): RSD values are ≤15% and ≤23%, LOD values are 2.9-5.8 and 0.05-0.34 μg mL, recovery ranges are 96-105% and 91-111%. In addition, the influence of excessive concentrations of some main endogenous components of the body fluids on the analytical signal was studied. This step was used to evaluate possible limitations of the assay associated with the deviation of the composition of the body fluid matrix. Therefore, accounting for the short analysis time (≤15 min) and the use of a portable Raman spectrometer, the proposed assay can be suggested for therapeutic drug monitoring in hospitals.
Topics: Humans; Cyclodextrins; Metal Nanoparticles; Silver; Anti-Bacterial Agents; Spectrum Analysis, Raman; Fluoroquinolones; Body Fluids; Plasma
PubMed: 36462278
DOI: 10.1016/j.talanta.2022.124083 -
Micromachines Nov 2023By using melamine as a precursor for the copolymerization process, g-CN and g-CN/TCNQ/Eu complexes with various amounts of doping were created. These complexes were then...
By using melamine as a precursor for the copolymerization process, g-CN and g-CN/TCNQ/Eu complexes with various amounts of doping were created. These complexes were then examined using XRD, FT-IR, SEM, TEM, XPS, PL, UV-vis, and I-T. The degradation rates of pefloxacin (PEF), enrofloxacin (ENR), and ciprofloxacin (CIP) were 91.1%, 90.8%, and 93.2% under visible light (λ > 550 nm). The photocatalytic performance of the composite was analyzed, and the best effect was obtained for CIP photocatalysis when Eu doping was 3 mg at 20 °C and pH 7. Kinetic analysis showed that there was a linear relationship between the sample and the photocatalytic time, and the degradation rate was about 5 times that of g-CN. The cyclic stability of the g-CN/TCNQ/Eu composite sample was found to be good through repeated experiments. UPLC-MS visualizes the degradation process of CIP. The extremely low stability of piperazine ring induced subsequent degradation, followed by the fracture of quinolone ring promoting the complete decomposition of CIP.
PubMed: 38138315
DOI: 10.3390/mi14122146 -
Ecotoxicology and Environmental Safety Jan 2023Based on self-report questionnaires, two previous epidemiological studies investigated the association between the exposure of women to antibiotics and their fertility....
BACKGROUND
Based on self-report questionnaires, two previous epidemiological studies investigated the association between the exposure of women to antibiotics and their fertility. However, biomonitoring studies on low-dose antibiotic exposure, mainly from food and water, and its relation to the risk of infertility are missing.
METHODS
Based on a case-control study design, 302 women with infertility (144 primary infertility, 158 secondary infertility) and 302 women with normal fertility, all aged 20-49 years, were recruited from Anhui Province, China, in 2020 and 2021. A total of 41 common antibiotics and two antibiotic metabolites in urine samples were determined by liquid chromatography-triple quadrupole tandem mass spectrometry (LC-QqQ-MS/MS).
RESULTS
Twenty-eight antibiotics with detection rates from 10% to 100% in both cases (median concentration: ∼2.294 ng/mL) and controls (∼1.596 ng/mL) were included in the analysis. Logistic regression analysis revealed that after controlling for confounding factors, high concentrations of eight individual antibiotics (sulfamethoxazole, sulfaclozine, sulfamonomethoxine, penicillin G, chlorotetracycline, ofloxacin, norfloxacin, and cyadox) and four antibiotic classes (sulfonamides, tetracyclines, quinoxalines, and veterinary antibiotics) were related to a high risk of female infertility, with odds ratios (ORs) ranging from 1.30 to 2.86, except for chlorotetracycline (OR = 6.34), while another nine individual antibiotics (sulfamethazine, azithromycin, cefaclor, amoxicillin, oxytetracycline, pefloxacin, sarafloxacin, enrofloxacin, and florfenicol) and classes of chloramphenicol analogs and human antibiotics were related to a reduced risk of infertility, with ORs ranging from 0.70 to 0.20. Based on restricted cubic spline models after controlling for confounding factors, we observed that the relationship between all of the above protective antibiotics and infertility was nonlinear: A certain concentration could reduce the risk of female infertility while exceeding a safe dose could increase the risk of infertility.
CONCLUSION
These results provide preliminary evidence that the effects of antibiotics on female fertility vary based on the active ingredient and usage and imply the importance of exposure dose. Future studies are needed to verify these results by controlling for multiple confounding factors.
Topics: Humans; Female; Anti-Bacterial Agents; Tandem Mass Spectrometry; Chlortetracycline; Infertility, Female; Case-Control Studies; China
PubMed: 36516626
DOI: 10.1016/j.ecoenv.2022.114414 -
Molecular Diversity Apr 2022Pefloxacin-based mixed ligand Cu(II) complexes with substituted isatin of type [Cu(Isatin)(Pefloxacin)Cl] were synthesized, and characterized by EPR, mass, FT-IR,...
Pefloxacin-based mixed ligand Cu(II) complexes with substituted isatin of type [Cu(Isatin)(Pefloxacin)Cl] were synthesized, and characterized by EPR, mass, FT-IR, electronic spectrometry, metal content, magnetic moment, and conductance measurement. The g factors g [Formula: see text] > g [Formula: see text] > 2.0023 observed in EPR suggest a square-pyramidal environment of ligands around the copper metal. The compounds were screened for diverse biological activities. The compounds inhibit efficiently the cell proliferation of HCT 116 cancer cells. To take the insight of anticancer activity mechanism, we investigated compound-1 for further cellular assay-based biological activities like trypan blue assay, cell morphological alteration assay, colony formation assay, cell apoptosis, and cell necrosis assay. The compound-1 induced distinct morphological alteration in cells, inhibits cell viability, decreases % plating efficiency, and decreases the clonogenic ability of the HCT 116 cells. The cell death mechanism was confirmed by annexin V-FITC / PI assay and LDH release assay. The positive annexin V/PI stained cells in presence of compound-1 and the absence of a significant amount of lactate dehydrogenase suggest cell apoptosis mechanism for anticancer activity of compounds. We also screened compounds for in vitro antibacterial and cytotoxic activities. Synthesis, characterization, antibacterial, anticancer, and cytotoxicity activities of pefloxacin based Cu(II) complexes were studied. The compound -1 is more potent than standard anticancer drugs and it induced apoptosis to the HCT 116 cells.
Topics: Anti-Bacterial Agents; Antineoplastic Agents; Copper; Fluoroquinolones; Humans; Isatin; Ligands; Pefloxacin; Spectroscopy, Fourier Transform Infrared
PubMed: 33646502
DOI: 10.1007/s11030-021-10199-2 -
Journal of Clinical Microbiology Nov 2015Fluoroquinolones (FQs) are among the drugs of choice for treatment of Salmonella infections. However, fluoroquinolone resistance is increasing in Salmonella due to...
Fluoroquinolones (FQs) are among the drugs of choice for treatment of Salmonella infections. However, fluoroquinolone resistance is increasing in Salmonella due to chromosomal mutations in the quinolone resistance-determining regions (QRDRs) of the topoisomerase genes gyrA, gyrB, parC, and parE and/or plasmid-mediated quinolone resistance (PMQR) mechanisms including qnr variants, aac(6')-Ib-cr, qepA, and oqxAB. Some of these mutations cause only subtle increases in the MIC, i.e., MICs ranging from 0.12 to 0.25 mg/liter for ciprofloxacin (just above the wild-type MIC of ≤0.06 mg/liter). These isolates are difficult to detect with standard ciprofloxacin disk diffusion, and plasmid-mediated resistance, such as qnr, is often not detected by the nalidixic acid screen test. We evaluated 16 quinolone/fluoroquinolone disks for their ability to detect low-level-resistant Salmonella enterica isolates that are not serotype Typhi. A total of 153 Salmonella isolates characterized for the presence (n = 104) or absence (n = 49) of gyrA and/or parC topoisomerase mutations, qnrA, qnrB, qnrD, qnrS, aac(6')-Ib-cr, or qepA genes were investigated. All isolates were MIC tested by broth microdilution against ciprofloxacin, levofloxacin, and ofloxacin and by disk diffusion using EUCAST or CLSI methodology. MIC determination correctly categorized all isolates as either wild-type isolates (MIC of ≤0.06 mg/liter and absence of resistance genes) or non-wild-type isolates (MIC of >0.06 mg/liter and presence of a resistance gene). Disk diffusion using these antibiotics and nalidixic acid failed to detect some low-level-resistant isolates, whereas the 5-μg pefloxacin disk correctly identified all resistant isolates. However, pefloxacin will not detect isolates having aac(6')-Ib-cr as the only resistance determinant. The pefloxacin disk assay was approved and implemented by EUCAST (in 2014) and CLSI (in 2015).
Topics: Anti-Bacterial Agents; Bacteremia; Base Sequence; Ciprofloxacin; DNA Gyrase; DNA Topoisomerase IV; DNA, Bacterial; Disk Diffusion Antimicrobial Tests; Drug Resistance, Multiple, Bacterial; Humans; Levofloxacin; Nalidixic Acid; Ofloxacin; Pefloxacin; Salmonella Infections; Salmonella enterica; Sequence Analysis, DNA
PubMed: 26292292
DOI: 10.1128/JCM.01287-15