BACKGROUND Pseudomonas aeruginosa(P.aeruginosa)is an important cause of nosocomial infections,and contributes to high morbidity and mortality,especially in intensive care units.P.aeruginosa is considered a'critica...BACKGROUND Pseudomonas aeruginosa(P.aeruginosa)is an important cause of nosocomial infections,and contributes to high morbidity and mortality,especially in intensive care units.P.aeruginosa is considered a'critical'category bacterial pathogen by the World Health Organization to encourage an urgent need for research and development of new antibiotics against its infections.AIM To investigate the effectiveness of baicalin combined with tobramycin therapy as a potential treatment method for carbapenem-resistant P.aeruginosa(CRPA)infections.METHODS Polymerase chain reaction(PCR)and RT-PCR were used to detect the expression levels of drug-resistant genes(including VIM,IMP and OprD2)and biofilmrelated genes(including algD,pslA and lasR)in CRPA that confer resistance to tobramycin,baicalin and tobramycin combined with baicalin(0,1/8,1/4,1/2 and 1MIC).RESULTS There was a correlation between biofilm formation and the expression of biofilmrelated genes.In addition,VIM,IMP,OprD2,algD,pslA and lasR that confer biofilm production under different concentrations in CRPA were significantly correlated.The synergistic effect of baicalin combined with tobramycin was a significant down-regulation of VIM,IMP,algD,pslA and lasR.CONCLUSION Baicalin combined with tobramycin therapy can be an effective treatment method for patients with CRPA infection.展开更多
AIM： To compare the combination of fluorometholone0.1% and levofloxacin 0.5% to tobramycin/dexamethasone eye drops in controlling inflammation and preventing infection after phacoemulsification with an intraocular le...AIM： To compare the combination of fluorometholone0.1% and levofloxacin 0.5% to tobramycin/dexamethasone eye drops in controlling inflammation and preventing infection after phacoemulsification with an intraocular lens implantation.METHODS： Sixty eyes from 60 patients undergoing cataract phacoemulsification were randomized into two groups; half of the patients were treated with fluorometholone（6 times/d） combined with levofloxacin（4 times/d）, while the other half were treated with tobramycin/dexamethasone（4 times/d） eye drops for one week. Preoperative and postoperative intraocular pressure, aqueous flare, corneal thickness, and signs and symptoms were recorded before the operation and1 wk following treatments. RESULTS： There were no statistically significant differences between the two groups in corneal thickness（P ≥0.629）, aqueous flare（P ≥0.398）, and signs and symptoms scores（P ≥0.350） at each time point. Ocular hypertension was only observed in two eyes in the tobramycin/dexamethasone group. CONCLUSION： Fluorometholone combined with levofloxacin treatment shows comparable efficacy but without the tendency to increase intraocular pressure;thus, it might be a better regimen for postoperative use.展开更多
Tobramycin is one of the aminoglycoside antibiotics that lack a UV absorbing chromophore. However, the application of pulsed electrochemical detection （PED） has been used successfully for the analysis of this and si...Tobramycin is one of the aminoglycoside antibiotics that lack a UV absorbing chromophore. However, the application of pulsed electrochemical detection （PED） has been used successfully for the analysis of this and similar antibiotics. This work describes an improved liquid chromatographic （LC） method combined with PED, which is able to separate much more impurities than before. Using a Discovery C-18 RP column （250 mm × 4.6 mm i.d., 5 μm）, isocratic elution was carried out with a mobile phase, containing sodium sulfate （35 g/L）, sodium octanesulphonic acid （1 g/L）, tetrahydrofuran （14mL/L） and 0.2 M phosphate buffer pH 3.0 （50 mL/L）. Using these experimental conditions, the limit of quantification （LOQ, S/N= 10） was 5 ng. The linearity was examined in the range LOQ-60 μg/mL and the coefficient of determination was 0.998. The method also proved to be repeatable and the recovery was close to 100%. The influence of the different chromatographic parameters on the separation was investigated by means of an experimental design. The proposed method is useful in quality control of tobramycin drug substances and drug products.展开更多
A simple and direct method without a deriva- tion step for routine analysis of tobramycin has been developed. This method used reversed-phase ion-pair high performance liquid chromatography （HPLC） with a refractive ...A simple and direct method without a deriva- tion step for routine analysis of tobramycin has been developed. This method used reversed-phase ion-pair high performance liquid chromatography （HPLC） with a refractive index （RI） detector and a C18 column which is stable at pH above 1.00. The presence of 4.50mg.mL ] trifluoroacetic acid （TFA） in the mobile phase improved the protonation of tobramycin and the formation of ionpairs, and thus reduced its hydrophility. This unique separation-detection combination showed good linearity with correlation coefficients 0.9996 in the concentration range of 0.25-2.50mg.mL 1. The quantitation limit and detection limit were determined to be 0.23 mg.mL ~ and 0.071 mg. mL ~, respectively. Tobramycin was recovered in 98.00%, 98.84% and 99.64% for tobramycin solutions at concentrations of 2.25 mg.mL^-1, 1.50mg.mL 1 and 0.75 mg.mL ＇, respectively. The relative standard deviations for six spiked samples ranged from 0.20% to 2.40%, indicating a good reproducibility of this method.展开更多
基金Supported by Jiaxing Science and Technology Planning Project,No.2019AY32006 and No.2020AY30004。
文摘BACKGROUND Pseudomonas aeruginosa(P.aeruginosa)is an important cause of nosocomial infections,and contributes to high morbidity and mortality,especially in intensive care units.P.aeruginosa is considered a'critical'category bacterial pathogen by the World Health Organization to encourage an urgent need for research and development of new antibiotics against its infections.AIM To investigate the effectiveness of baicalin combined with tobramycin therapy as a potential treatment method for carbapenem-resistant P.aeruginosa(CRPA)infections.METHODS Polymerase chain reaction(PCR)and RT-PCR were used to detect the expression levels of drug-resistant genes(including VIM,IMP and OprD2)and biofilmrelated genes(including algD,pslA and lasR)in CRPA that confer resistance to tobramycin,baicalin and tobramycin combined with baicalin(0,1/8,1/4,1/2 and 1MIC).RESULTS There was a correlation between biofilm formation and the expression of biofilmrelated genes.In addition,VIM,IMP,OprD2,algD,pslA and lasR that confer biofilm production under different concentrations in CRPA were significantly correlated.The synergistic effect of baicalin combined with tobramycin was a significant down-regulation of VIM,IMP,algD,pslA and lasR.CONCLUSION Baicalin combined with tobramycin therapy can be an effective treatment method for patients with CRPA infection.
文摘AIM： To compare the combination of fluorometholone0.1% and levofloxacin 0.5% to tobramycin/dexamethasone eye drops in controlling inflammation and preventing infection after phacoemulsification with an intraocular lens implantation.METHODS： Sixty eyes from 60 patients undergoing cataract phacoemulsification were randomized into two groups; half of the patients were treated with fluorometholone（6 times/d） combined with levofloxacin（4 times/d）, while the other half were treated with tobramycin/dexamethasone（4 times/d） eye drops for one week. Preoperative and postoperative intraocular pressure, aqueous flare, corneal thickness, and signs and symptoms were recorded before the operation and1 wk following treatments. RESULTS： There were no statistically significant differences between the two groups in corneal thickness（P ≥0.629）, aqueous flare（P ≥0.398）, and signs and symptoms scores（P ≥0.350） at each time point. Ocular hypertension was only observed in two eyes in the tobramycin/dexamethasone group. CONCLUSION： Fluorometholone combined with levofloxacin treatment shows comparable efficacy but without the tendency to increase intraocular pressure;thus, it might be a better regimen for postoperative use.
文摘Tobramycin is one of the aminoglycoside antibiotics that lack a UV absorbing chromophore. However, the application of pulsed electrochemical detection （PED） has been used successfully for the analysis of this and similar antibiotics. This work describes an improved liquid chromatographic （LC） method combined with PED, which is able to separate much more impurities than before. Using a Discovery C-18 RP column （250 mm × 4.6 mm i.d., 5 μm）, isocratic elution was carried out with a mobile phase, containing sodium sulfate （35 g/L）, sodium octanesulphonic acid （1 g/L）, tetrahydrofuran （14mL/L） and 0.2 M phosphate buffer pH 3.0 （50 mL/L）. Using these experimental conditions, the limit of quantification （LOQ, S/N= 10） was 5 ng. The linearity was examined in the range LOQ-60 μg/mL and the coefficient of determination was 0.998. The method also proved to be repeatable and the recovery was close to 100%. The influence of the different chromatographic parameters on the separation was investigated by means of an experimental design. The proposed method is useful in quality control of tobramycin drug substances and drug products.
文摘A simple and direct method without a deriva- tion step for routine analysis of tobramycin has been developed. This method used reversed-phase ion-pair high performance liquid chromatography （HPLC） with a refractive index （RI） detector and a C18 column which is stable at pH above 1.00. The presence of 4.50mg.mL ] trifluoroacetic acid （TFA） in the mobile phase improved the protonation of tobramycin and the formation of ionpairs, and thus reduced its hydrophility. This unique separation-detection combination showed good linearity with correlation coefficients 0.9996 in the concentration range of 0.25-2.50mg.mL 1. The quantitation limit and detection limit were determined to be 0.23 mg.mL ~ and 0.071 mg. mL ~, respectively. Tobramycin was recovered in 98.00%, 98.84% and 99.64% for tobramycin solutions at concentrations of 2.25 mg.mL^-1, 1.50mg.mL 1 and 0.75 mg.mL ＇, respectively. The relative standard deviations for six spiked samples ranged from 0.20% to 2.40%, indicating a good reproducibility of this method.
