Study Of Three Fluoroquinolones Residues Determination By Sensitization Microbiological Method With Reserpine

For searching which Fluoroquinolones residues were detected by microbiol ogical assay and the effection of fluoroquinolones were exsensitived with reserp ine and degree of The minimal detectable were reduced.A cylinder plate micr obiological assay with StaphylococcusAureus(CMCC(B)26003),BacillusPumilus (CMCC(B)63202),EscherichiaColi(CMCC(B)44103),BacillusSubtilis(CMCC(B)635 01) and MicrococcusLuteus(CMCC(B)10240)was developed for determination o fFluoroquinolones(Enrofloxacin.Ciprofloxacin and Levofloxacin) residues And st udy of sensitization method determination of Fluoroquinolones residues with res erpine.1.The establishment of microbiological method for three fluoroquinolones residues1.1 The collection of the feasible inoclum concentration of seed ager with the five bactria and pH value of substrate.The concentration of bacteria and pH value of substrate were confirmed b y the inhibition zone diameters and the definition at different moment.The resu lts showed that:When the inoclum concentration were 0.35%(5×10~5CFU/ml),0. 4%(6×10~6CFU/ml),0.2%(12×10~5CFU/ml),0.2%(6×10~5CFU/ml)and 0.8%(12×10~5CFU/ml) of the Staphylococcus Aureus,Bacillus Purnilus,Escherichia Coli,Bac illus Subtilis and Micrococcus Luteus respectibely,the inhibition zone biggest d iameters,and the edges were smooth.And the best PH value of substrate was 6.5.1.2 The standard response curves of three Fluoroquinolones in Phosphate-Buffered Saline(PBS).The research prepared the standard response curves of three Fluoroquinolones to five bacteria in PBS.The results:The coefficients variations(C.V.) of the slopes were below than 10%;and the correlation variation were above than 0.998.These showed that the experiment had good repetition,and the inhibition zone diameters with the logarithm of drug concentration had positive correlation.1.3 The minimal detectable of three Fluoroquinolones in Phosphate-Buffered Saline(PBS).The minimal detection were confirmed by the determination of the inhibition zone diameters with three drugs and five bacteria.The results:In PBS,there were differences time The minimal detectable of the same drug with the different bacteria; and there were the differences time The minimal detectable of the different drugs with the same bacterium.With these five bacteria,The minimal detectable of ENR was 0.063-0.13μg/ml,and The minimal detectable of CIP was 0.25-2.0μg/ml,and The minimal detectable of LEV was 0.5-1.0μg/ml.2.study of sensitivity method for The mixture of reserpine and three Fluoroquinolones residues2.1 The preparation of the standard response curves of The mixture of reserpine and three Fluoroquinolones in Phosphate-Buffered Saline(PBS).The results:The coefficients variations(C.V.) of the slopes were below than 10%; and the correlation variation were above than 0.998.The results that the experiment had good repetition,and the inhibition zone diameters with the logarithm of drug concentration had positive correlation.2.2 The minimal detectable of The mixture of reserpine and three Fluoroquinolones in Phosphate-Buffered Saline(PBS).The minimal detectable were confirmed by the determination of the inhibition zone diameters with three drugs and five bacteria.The results:In PBS,there were differences among The minimal detectable of the same drug with the different bacteria; and there were the differences among The minimal detectable of the different drugs with the same bacterium.With these five bacteria,The minimal detectable of the mixture of reserpine and ENR was 0.0078-0.016μg/ml,and The minimal detectable of the mixture of reserpine and CIP was 0.010-0.063μg/ml,and The minimal detectable of the mixture of reserpine and LEV was 0.016-0.13μg/ml.In summary,Microbiological method detected Fluoroquinolones residues sensitizationed by reserpine was established in the research.RSD in 10%;The limit detection of three Fluoroquinolones drops 6-10 times separately by sensitization with reserpine,relevance ratio of Fluoroquinolones was increased effectively,sensitivity of microbiological method was improved,scientific basis was offered for work of prescreening.