評估以氯黴素生物測定法分析牛奶中四環黴素殘留量之效果   全文下載

Effect of Chloramphenicol on a Bioassay Response for the Detection of Tetracycline Residues in Milk

四環黴素類是廣泛使用的動物用藥，最大殘留容許量並不總是能以Geobacillus stearothermophilus subsp. calidolactis C-953 微生物抑制法檢測出來。為改善這些方法的靈敏度，本生物測定法評估培養基中併用不同濃度氯黴素（CAP）的效果，分析牛奶中6 種四環黴素的專一度和檢出限量。當CAP 濃度增加時，其專一度由97.9%（CAP 濃度為 0, 50, 200 及400 μg/kg）下降至88.0%（CAP 濃度為600 μg/kg）。羅吉斯迴歸模式顯示CAP 濃度的多寡有明顯影響。然而四環黴素與氯黴素的交互作用並不明顯，因此不能認為兩個抗生素比單一種抗生素更具有加乘效果。當氯黴素的濃度由0 增加至400 μg/kg 時，檢出限量有減少趨勢，chlortetracycline 由590 μg/kg 降低至316 μg/kg、doxycycline 由115 μg/kg 降低至62 μg/kg、meclocycline 由105 μg/kg 降低至52 μg/kg、oxytetracycline 由446 μg/kg 降低至273 μg/kg、rolitetracycline 由 191 μg/kg 降低至134 μg/kg 及Tetracycline 由302 μg/kg 降低至158 μg/kg。"

The tetracyclines are commonly used in veterinary medicine, and yet the residues are not always detected by microbiological inhibitor tests using Geobacillus stearothermophilus subsp. calidolactis C-953 at their Maximum Residue Limit levels. In order to improve the sensitivity of these methods, a bioassay was evaluated to study the effect produced by the incorporation of different chloramphenicol (CAP) concentrations in the culture medium. The specificity and detection limits of six tetracyclines in milk were determined. As the levels of CAP increased, a decrease in specificity, from 97.9% (for 0, 50, 200 and 400 μg/kg of CAP) to 88.0% (for 600 μg/kg of CAP) was observed. The logistic regression model indicates a significant effect of the CAP concentration. However, the tetracycline-CAP interaction was not significant, and thus, a synergetic effect can not be considered between the two antimicrobials, with only a simple sum of their antimicrobial effects. When the CAP concentration is increased from 0 to 400 μg/kg, the detection limits of chlortetracycline (590 μg/kg-316 μg/kg), doxycycline (115 μg/kg-62 μg/kg), meclocycline (105 μg/kg- 52 μg/kg), oxytetracycline (446 μg/kg-273 μg/kg), rolitetracycline (191 μg/kg-134 μg/kg) and tetracycline (302 μg/kg-158 μg/kg) are observed to decrease.