Staphylococci strains, like the majority of bacterial strains, have developed the resistance to several antibiotics, including Quinolones and Fluoroquin-olones In the Republic of the Congo, cases of resistance leading...Staphylococci strains, like the majority of bacterial strains, have developed the resistance to several antibiotics, including Quinolones and Fluoroquin-olones In the Republic of the Congo, cases of resistance leading to treat-ment failures have been observed during the treatment of staphylococcal infections with antibiotics in hospitals. The objective of this study was to identify the Quinolone/Fluoroquinolone resistance genes from staphylo-cocci strains isolated in hospitals. A total of 51 strains of Staphylococci were isolated, including 16 (31.37%) community strains, and 35 (68.62%) clinical strains. 46 strains of Staphylococcus aureus (S. aureus) and 5 SCNs were identified. A total of 34 DNA fragments from different strains resistant to Quinolones/Fluoroquinolones, including 21 (61.67%) DNA fragments from clinical S. aureus and 13 (38.23%) from community SCN strains were analyzed by the molecular method (genotypic detection) by PCR. The genotypic results made it possible to identify the gyrA, grLA and norA genes and to show that these genes are involved in the resistance of the strains to the various antibiotics used. The grLA gene was the most identified gene with a frequency of 75%. The gyrA and grLA genes have been identified in Staphylococcus aureus and Coagulase Negative Staphy-lococci. The norA gene, on the other hand, has only been identified in Staphylococcus aureus. Two mechanisms are essentially involved in the resistance of Staphylococci to quinolones/Fluoroquinolones, the mecha-nism of resistance by efflux, which takes place thanks to a transmembrane protein coded by the norA gene and by point mutations (substitution and deletion of acids or nucleotides) observed within the protein and nucleic sequences of the chromosomal gyrA and grLA genes.展开更多
Staphylococcus aureus is a common marine foodborne pathogen.In this study,antibiotics ciprofloxacin and enrofloxacin were used to induce drug-resistance in S.aureus.The differentially expressed proteins(DEPs)were anal...Staphylococcus aureus is a common marine foodborne pathogen.In this study,antibiotics ciprofloxacin and enrofloxacin were used to induce drug-resistance in S.aureus.The differentially expressed proteins(DEPs)were analyzed and compared with those in the bacteria cultured without antibiotics.The primary proteomic alterations were in the levels of cell membrane components and proteins related to lysine and folic acid biosynthesis,which were all significantly up-regulated.The minimal inhibitory concentrations(MIC)for both test drugs were elevated to 10μg m L^(-1)following serial passaging.These results indicated that,for both ciprofloxacin and enrofloxacin,drug-resistance were developed even in the subinhibitory levels and the primary response was a major alteration in the cell membrane proteome.These changes were similar to those observed in S.aureus cultured with super-MIC levels of these antibiotics.The current study provides a theoretical basis for in-depth study of the related changes of marine foodborne pathogens in subinhibitory concentrations that are commonly found in situ.展开更多
An efficient method is provided to detect simultaneously some important veterinary drugs from different classes in highly complex animal tissue matrix. This method using matrix solid-phase dispersion (MSPD) and high p...An efficient method is provided to detect simultaneously some important veterinary drugs from different classes in highly complex animal tissue matrix. This method using matrix solid-phase dispersion (MSPD) and high performance liquid chromatography (HPLC) with diode array detection (DAD) is developed to effectively determine two fiuoroquinolones (enoxacin and lomefioxacin), two sulfonamides (sulfanilamide and sulfamethoxazole) and one tetracycline (tetracycline) simultaneously in porcine tissues. In the process, MSPD methodology was used to treat samples, washed by n-hexane to remove lipid, eluted the analytes with acetonitrile–dichloromethane (1:1, v/v). Solvent acetonitrile and solvent acetic acid (0.1%) were combined in a gradient. HPLC–DAD analysis of the tissue samples was performed within 15 min at a fiow rate of 1.0 mL/min. The results showed that a recovery at 0.1, 0.5 and 1.0 mg/g fortification levels ranged from 80.6% to 99.2% with satisfactory relative standard deviations (RSDs) (below 6.1%, nfi3) and the limits of quantitation (LOQ) ranged from 7 mg/kg to 34 mg/kg in porcine tissues. Utilization of the method in successfully simultaneous analysis of porcine tissue incurred with veterinary drug multiresidues is described.展开更多
Solid organ transplantation(SOT)is the best treatment option for end-stage organ disease.Newer immunosuppressive agents have reduced the incidence of graft rejection but have increased the risk of infection,particular...Solid organ transplantation(SOT)is the best treatment option for end-stage organ disease.Newer immunosuppressive agents have reduced the incidence of graft rejection but have increased the risk of infection,particularly due to the reactivation of latent infections due to opportunistic agents such as Mycobacterium tuberculosis.Active tuberculosis(TB)after SOT is a significant cause of morbidity and mortality.Most cases of posttransplant TB are secondary to reactivation of latent tuberculosis infection(LTBI)due to the effects of long-term immunosuppressive therapy.Risk minimization strategies have been developed to diagnose LTBI and initiate treatment prior to transplantation.Isoniazid with vitamin B6 supplementation is the treatment of choice.However,liver transplantation(LT)candidates and recipients have an increased risk of isoniazid-induced liver toxicity,leading to lower treatment completion rates than in other SOT populations.Fluoroquinolones(FQs)exhibit good in vitro antimycobacterial activity and a lower risk of drug-induced liver injury than isoniazid.In the present review,we highlight the disease burden posed by posttransplant TB and summarize the emerging clinical evidence supporting the use of FQs for the treatment of LTBI in LT recipients and candidates.展开更多
Nine strains resistant to five fluoroquinolones （Ciprofloxacin, Ofloxacin, Enrofloxacin, Danofloxacin, Sarafloxacin） were isolated from clinical samples and extracted the chromosomal DNA of these strains. Designed p...Nine strains resistant to five fluoroquinolones （Ciprofloxacin, Ofloxacin, Enrofloxacin, Danofloxacin, Sarafloxacin） were isolated from clinical samples and extracted the chromosomal DNA of these strains. Designed primers to amplify the Quinolone-resistance-determining region （QRDR） of gyrA and par（？,, then the PCR products were sequenced and analyzed. In comparision with NCTC5776, a single mutation was found at base 371 in gyrA of strain 38 which changed from C to T, and a single mutation was found at base 350 in gyrA of strain 60 which changed from A to C. No mutation was found in gyrA of the rest The mutation of strain 38 led to an amino acid substitution of Arg99Cys and the mutation of 60 led to an amino acid substitution of Met 92 Leu. No mutation was found in parC QRDR of all the isolates. These results indicats that the DNA gyrase will be the primary target to salmonella of fluoroquinolone.展开更多
AIMTo compare the conjunctival epithelial toxicities of three newer-generation fluoroquinolones without preservatives.METHODSIn a prospective, randomized, double blind comparative study, 47 eyes of 47 patients with a ...AIMTo compare the conjunctival epithelial toxicities of three newer-generation fluoroquinolones without preservatives.METHODSIn a prospective, randomized, double blind comparative study, 47 eyes of 47 patients with a primary pterygium were enrolled, and divided randomly into three groups (levofloxacin 0.5%, gatifloxacin 0.3%, and moxifloxacin 0.5%). After pterygium surgery with the same conjunctival autograft technique, each patient maintained a regimen with a randomly assigned fluoroquinolone eye drop. Patients were examined every other day after surgery until the epithelium had completely healed. Photos were taken and used to measure the area of residual epithelial defects. Conjunctival healing time and speed (initial defect area/healing time (mm<sup>2</sup>/d) compared in each group using Kruskal-Wallis tests.RESULTSThere were no significant differences in mean age, gender, and conjunctival defect size of the donor site between these groups. However, the mean of conjunctival healing time and speed were statistically different in each group. The mean of conjunctival epithelial healing time was 8.93±2.69d (levofloxacin group), 10.31±2.96d (gatifloxacin group), and 13.50±4.10d (moxifloxacin group), P=0.006. The mean conjuctival epithelial healing speed was 6.18±1.39 mm<sup>2</sup>/d (levofloxacin group), 5.52±1.68 mm<sup>2</sup>/d (gatifloxacin group), and 4.40±1.30 mm<sup>2</sup>/d (moxifloxacin group), P=0. 003.CONCLUSIONWithout the influence of preservatives, levofloxacin and gatifloxacin might be less toxic to the regeneration of conjunctival epithelial cells and cause a faster conjunctival wound healing relative to moxifloxacin.展开更多
The PM3 and B3LYP methods were employed to calculate the properties of 18 7-substituted fluoroquinolones. The correlation between biological activity （against gram-positive organisms or gram-negative organisms） and ...The PM3 and B3LYP methods were employed to calculate the properties of 18 7-substituted fluoroquinolones. The correlation between biological activity （against gram-positive organisms or gram-negative organisms） and structural properties was obtained by using multiple linear regression （MLR） methods： The best model generated correlates the antibacterial activity with EHOMO and QF8 for gram-positive organisms, and EHOMO and dipole moment for gram-negative organisms, respectively. It suggests that the interaction mechanisms ,of fluoroquinolons with gram-positive and gram-negative organisms are different.展开更多
Ciprofloxacin（CIP）, moxifoxacin（MOX） and enrofloxacin（ENR） were selected as typical fluoroquinolones（FQs） to analyze the excitation-enhancing effect and mechanism of solvents on FQs＇ electron transition based...Ciprofloxacin（CIP）, moxifoxacin（MOX） and enrofloxacin（ENR） were selected as typical fluoroquinolones（FQs） to analyze the excitation-enhancing effect and mechanism of solvents on FQs＇ electron transition based on quantum chemical calculations. The UV spectra of three FQs in gas and five different solvents（water, cyclohexane, dimethylsulfoxide, methanol, acetone） were calculated using Gaussian 09 software. The transition mechanisms of FQs＇ main electron transitions were analyzed by natural bond orbital（NBO） theory, and the solvent effect on each electron transition was assessed qualitatively and quantitatively by sensitivity analysis and an established index system. The excitation enhancing mechanism of solvent on electron transitions of FQs was analyzed from the view of photo-induced reactions between solvent and FQs molecules. The results show that there are two main transitions located in the spectrum ranges of 300~380 and 240~300 nm for each FQ in any medium, which are assigned as n →π＊ and π→π＊ electron transitions, respectively. By comparison, the n →π＊ transition is more sensitive to solvent because of the energy transfer between solvent molecules and FQs, but the solvent effect on the π→π＊ transition is stronger than on the n →π＊ transition. The sequence of affected extent of solvent effect on electron transition was CIP 〉 MOX 〉 ENR, and the sequence of solvent effect was water 〉 DMSO 〉 methanol 〉 acetone 〉 cyclohexane（stronger solvent effect with increasing the dielectric constant of solvent）. From the view of photo-induced reactions, the reaction between FQs＊T1 and solvent＊T1 has the decisive regulatory effect on the n →π＊ transition of FQs in solvent, and the reaction between FQsS0 and solvent＊TI has an enhancing effect on the π→π＊ transition.展开更多
Aiming at the market demand for rapid detection of tetracyclines,fluoroquinolones and sulfonamides in milk,a golloidal gold immunochromatography test strip for simultaneous detection of tetracyclines,fluoroquinolones ...Aiming at the market demand for rapid detection of tetracyclines,fluoroquinolones and sulfonamides in milk,a golloidal gold immunochromatography test strip for simultaneous detection of tetracyclines,fluoroquinolones and sulfonamides in milk was prepared based on the principle of competitive inhibition immunochromatography. The performance indicators of the test strip were verified. The results showed that the test strip can simultaneously detect 4 tetracyclines,13 fluoroquinolones and 13 sulfonamides,and the detection limits all can meet the national residue limits; the tests strip exhibited false positive rate≤5% and false negative rate = 0; and no cross-reaction with other drugs was commonly found in milk,indicating good specificity. The method is simple,rapid,and has low cost and easy popularization. It provides a means for realizing on-site rapid detection and is of important practical significance to guarantee of safety of milk and dairy products in China.展开更多
文摘Staphylococci strains, like the majority of bacterial strains, have developed the resistance to several antibiotics, including Quinolones and Fluoroquin-olones In the Republic of the Congo, cases of resistance leading to treat-ment failures have been observed during the treatment of staphylococcal infections with antibiotics in hospitals. The objective of this study was to identify the Quinolone/Fluoroquinolone resistance genes from staphylo-cocci strains isolated in hospitals. A total of 51 strains of Staphylococci were isolated, including 16 (31.37%) community strains, and 35 (68.62%) clinical strains. 46 strains of Staphylococcus aureus (S. aureus) and 5 SCNs were identified. A total of 34 DNA fragments from different strains resistant to Quinolones/Fluoroquinolones, including 21 (61.67%) DNA fragments from clinical S. aureus and 13 (38.23%) from community SCN strains were analyzed by the molecular method (genotypic detection) by PCR. The genotypic results made it possible to identify the gyrA, grLA and norA genes and to show that these genes are involved in the resistance of the strains to the various antibiotics used. The grLA gene was the most identified gene with a frequency of 75%. The gyrA and grLA genes have been identified in Staphylococcus aureus and Coagulase Negative Staphy-lococci. The norA gene, on the other hand, has only been identified in Staphylococcus aureus. Two mechanisms are essentially involved in the resistance of Staphylococci to quinolones/Fluoroquinolones, the mecha-nism of resistance by efflux, which takes place thanks to a transmembrane protein coded by the norA gene and by point mutations (substitution and deletion of acids or nucleotides) observed within the protein and nucleic sequences of the chromosomal gyrA and grLA genes.
基金funded by the Professional Innovation and Integration Project of Qingdao University(2020)。
文摘Staphylococcus aureus is a common marine foodborne pathogen.In this study,antibiotics ciprofloxacin and enrofloxacin were used to induce drug-resistance in S.aureus.The differentially expressed proteins(DEPs)were analyzed and compared with those in the bacteria cultured without antibiotics.The primary proteomic alterations were in the levels of cell membrane components and proteins related to lysine and folic acid biosynthesis,which were all significantly up-regulated.The minimal inhibitory concentrations(MIC)for both test drugs were elevated to 10μg m L^(-1)following serial passaging.These results indicated that,for both ciprofloxacin and enrofloxacin,drug-resistance were developed even in the subinhibitory levels and the primary response was a major alteration in the cell membrane proteome.These changes were similar to those observed in S.aureus cultured with super-MIC levels of these antibiotics.The current study provides a theoretical basis for in-depth study of the related changes of marine foodborne pathogens in subinhibitory concentrations that are commonly found in situ.
基金supported by the Natural Science Foundation of Shaanxi Province (No. 2009jm4002-1)
文摘An efficient method is provided to detect simultaneously some important veterinary drugs from different classes in highly complex animal tissue matrix. This method using matrix solid-phase dispersion (MSPD) and high performance liquid chromatography (HPLC) with diode array detection (DAD) is developed to effectively determine two fiuoroquinolones (enoxacin and lomefioxacin), two sulfonamides (sulfanilamide and sulfamethoxazole) and one tetracycline (tetracycline) simultaneously in porcine tissues. In the process, MSPD methodology was used to treat samples, washed by n-hexane to remove lipid, eluted the analytes with acetonitrile–dichloromethane (1:1, v/v). Solvent acetonitrile and solvent acetic acid (0.1%) were combined in a gradient. HPLC–DAD analysis of the tissue samples was performed within 15 min at a fiow rate of 1.0 mL/min. The results showed that a recovery at 0.1, 0.5 and 1.0 mg/g fortification levels ranged from 80.6% to 99.2% with satisfactory relative standard deviations (RSDs) (below 6.1%, nfi3) and the limits of quantitation (LOQ) ranged from 7 mg/kg to 34 mg/kg in porcine tissues. Utilization of the method in successfully simultaneous analysis of porcine tissue incurred with veterinary drug multiresidues is described.
基金“Plan Nacional de I+D+I”Instituto de Salud Carlos III(Fondo de Investigaciones Sanitarias [FIS] PI14/00174)+1 种基金ubdirección General de Redes y Centros de Investigación Cooperativa,Spanish Ministry of Science,Innovation and Universities,Spanish Network for Research in Infectious Diseases(REIPI RD16/0016)cofinanced by the European Development Regional Fund(EDRF)"A way to achieve Europe"
文摘Solid organ transplantation(SOT)is the best treatment option for end-stage organ disease.Newer immunosuppressive agents have reduced the incidence of graft rejection but have increased the risk of infection,particularly due to the reactivation of latent infections due to opportunistic agents such as Mycobacterium tuberculosis.Active tuberculosis(TB)after SOT is a significant cause of morbidity and mortality.Most cases of posttransplant TB are secondary to reactivation of latent tuberculosis infection(LTBI)due to the effects of long-term immunosuppressive therapy.Risk minimization strategies have been developed to diagnose LTBI and initiate treatment prior to transplantation.Isoniazid with vitamin B6 supplementation is the treatment of choice.However,liver transplantation(LT)candidates and recipients have an increased risk of isoniazid-induced liver toxicity,leading to lower treatment completion rates than in other SOT populations.Fluoroquinolones(FQs)exhibit good in vitro antimycobacterial activity and a lower risk of drug-induced liver injury than isoniazid.In the present review,we highlight the disease burden posed by posttransplant TB and summarize the emerging clinical evidence supporting the use of FQs for the treatment of LTBI in LT recipients and candidates.
文摘Nine strains resistant to five fluoroquinolones （Ciprofloxacin, Ofloxacin, Enrofloxacin, Danofloxacin, Sarafloxacin） were isolated from clinical samples and extracted the chromosomal DNA of these strains. Designed primers to amplify the Quinolone-resistance-determining region （QRDR） of gyrA and par（？,, then the PCR products were sequenced and analyzed. In comparision with NCTC5776, a single mutation was found at base 371 in gyrA of strain 38 which changed from C to T, and a single mutation was found at base 350 in gyrA of strain 60 which changed from A to C. No mutation was found in gyrA of the rest The mutation of strain 38 led to an amino acid substitution of Arg99Cys and the mutation of 60 led to an amino acid substitution of Met 92 Leu. No mutation was found in parC QRDR of all the isolates. These results indicats that the DNA gyrase will be the primary target to salmonella of fluoroquinolone.
文摘AIMTo compare the conjunctival epithelial toxicities of three newer-generation fluoroquinolones without preservatives.METHODSIn a prospective, randomized, double blind comparative study, 47 eyes of 47 patients with a primary pterygium were enrolled, and divided randomly into three groups (levofloxacin 0.5%, gatifloxacin 0.3%, and moxifloxacin 0.5%). After pterygium surgery with the same conjunctival autograft technique, each patient maintained a regimen with a randomly assigned fluoroquinolone eye drop. Patients were examined every other day after surgery until the epithelium had completely healed. Photos were taken and used to measure the area of residual epithelial defects. Conjunctival healing time and speed (initial defect area/healing time (mm<sup>2</sup>/d) compared in each group using Kruskal-Wallis tests.RESULTSThere were no significant differences in mean age, gender, and conjunctival defect size of the donor site between these groups. However, the mean of conjunctival healing time and speed were statistically different in each group. The mean of conjunctival epithelial healing time was 8.93±2.69d (levofloxacin group), 10.31±2.96d (gatifloxacin group), and 13.50±4.10d (moxifloxacin group), P=0.006. The mean conjuctival epithelial healing speed was 6.18±1.39 mm<sup>2</sup>/d (levofloxacin group), 5.52±1.68 mm<sup>2</sup>/d (gatifloxacin group), and 4.40±1.30 mm<sup>2</sup>/d (moxifloxacin group), P=0. 003.CONCLUSIONWithout the influence of preservatives, levofloxacin and gatifloxacin might be less toxic to the regeneration of conjunctival epithelial cells and cause a faster conjunctival wound healing relative to moxifloxacin.
基金This work was supported by NNSFC (20563005) and partially supported by Center for Advanced Studies of Medicinal and Organic Chemistry of Yunnan University
文摘The PM3 and B3LYP methods were employed to calculate the properties of 18 7-substituted fluoroquinolones. The correlation between biological activity （against gram-positive organisms or gram-negative organisms） and structural properties was obtained by using multiple linear regression （MLR） methods： The best model generated correlates the antibacterial activity with EHOMO and QF8 for gram-positive organisms, and EHOMO and dipole moment for gram-negative organisms, respectively. It suggests that the interaction mechanisms ,of fluoroquinolons with gram-positive and gram-negative organisms are different.
文摘Ciprofloxacin（CIP）, moxifoxacin（MOX） and enrofloxacin（ENR） were selected as typical fluoroquinolones（FQs） to analyze the excitation-enhancing effect and mechanism of solvents on FQs＇ electron transition based on quantum chemical calculations. The UV spectra of three FQs in gas and five different solvents（water, cyclohexane, dimethylsulfoxide, methanol, acetone） were calculated using Gaussian 09 software. The transition mechanisms of FQs＇ main electron transitions were analyzed by natural bond orbital（NBO） theory, and the solvent effect on each electron transition was assessed qualitatively and quantitatively by sensitivity analysis and an established index system. The excitation enhancing mechanism of solvent on electron transitions of FQs was analyzed from the view of photo-induced reactions between solvent and FQs molecules. The results show that there are two main transitions located in the spectrum ranges of 300~380 and 240~300 nm for each FQ in any medium, which are assigned as n →π＊ and π→π＊ electron transitions, respectively. By comparison, the n →π＊ transition is more sensitive to solvent because of the energy transfer between solvent molecules and FQs, but the solvent effect on the π→π＊ transition is stronger than on the n →π＊ transition. The sequence of affected extent of solvent effect on electron transition was CIP 〉 MOX 〉 ENR, and the sequence of solvent effect was water 〉 DMSO 〉 methanol 〉 acetone 〉 cyclohexane（stronger solvent effect with increasing the dielectric constant of solvent）. From the view of photo-induced reactions, the reaction between FQs＊T1 and solvent＊T1 has the decisive regulatory effect on the n →π＊ transition of FQs in solvent, and the reaction between FQsS0 and solvent＊TI has an enhancing effect on the π→π＊ transition.
基金Supported by Hebei Science and Technology Program(16275507D)
文摘Aiming at the market demand for rapid detection of tetracyclines,fluoroquinolones and sulfonamides in milk,a golloidal gold immunochromatography test strip for simultaneous detection of tetracyclines,fluoroquinolones and sulfonamides in milk was prepared based on the principle of competitive inhibition immunochromatography. The performance indicators of the test strip were verified. The results showed that the test strip can simultaneously detect 4 tetracyclines,13 fluoroquinolones and 13 sulfonamides,and the detection limits all can meet the national residue limits; the tests strip exhibited false positive rate≤5% and false negative rate = 0; and no cross-reaction with other drugs was commonly found in milk,indicating good specificity. The method is simple,rapid,and has low cost and easy popularization. It provides a means for realizing on-site rapid detection and is of important practical significance to guarantee of safety of milk and dairy products in China.
