| 摘要: |
| 1993年9月至1995年末，大连地区的一龄鲍至成鲍都出现了脓疱病，用常规方法从3个养殖厂的病鲍中分离到了3个菌株，分别为D株、N株和T株。经鉴定这3个菌株为同一种—河流弧菌-Ⅱ。这3个菌株来自3个不同的海区、不同的单位，并且这3个单位使用的抗生素种类和浓度也不同，所以这3个菌株对18种抗生素的敏感度也不同。D株对环丙沙星（抑菌坏直径30mm）、复方新诺明（抑菌坏直径27mm）
等敏感，而对青霉素、青霉素Ⅱ、氨苄青霉素（抑菌环直径0mm）等耐药。N株除对青霉素Ⅱ、白霉素、吡哌酸等耐药外，对其它12种抗
生素都敏感或中度敏感（抑菌环直径13.5－30mm）。T株对氟派酸（抑菌环直径22mm）、环丙沙星（抑菌环直径20.3mm）等敏感，而对氯霉素、复方新诺明等耐药。研究发现，经常使用同一种抗生素很容易使病原菌产生耐药性．连续3d使用单一的抗生素（青霉素）就会产生耐药的菌株。为证明上述3个菌株的抗药性是属于哪一类，以T株为例，提取总DNA，并对总DNA进行EcoRⅠ酶切图谱分析，图谱有明显的异同，说明3个菌株的抗药性不同可能与基因突变有关。不管是非遗传型还是遗传型，都是由于抗生素为细菌提供了耐药突变株的选择环境，从而使耐药菌株得以大量繁殖。 |
| 关键词: 皱纹盘鲍 河流弧菌-Ⅱ 脓疱病 抗药机制 |
| DOI： |
| 分类号: |
| 基金项目:大连市科委重大资助项目，1994年44号 |
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| PRELIMINARY STUDIES ON THE MECHANISM OF VIBRIO FLUVIALIS— II RESISTANCE TO ANTIBIOTICS |
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Li Taiwu1, Ding Mingjin2, Song Xiemin2, Xiang Jianhai3, Liu Ruiyu3
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1.Department of Biology, Liaoning Normal University, Dalian 116029;2.Aquacultural Cmpany of Dalian, Dalian 116023;3.Institute of Oceanology, Chinese Academy of sciences, Qingdao 266071
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| Abstract: |
| The 1993 to 1995 outbreak of pustule disease of abalone Haliotis discus Hannai, discovered in the Dalian Coast (Aquacultural Company of Dalian, Pacific Aquacultural Company, New Harbor Aquacultural Company of Dalian) was caused by three strains (D, N and T) of the bacteria species Vibrio fluvialis- II, and were isolated with the routine method from the abalone foot. In this work, the sensitivity of V. fluvialis- II to 18 kinds of antibiotics and their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were studied. The sensitivity of V. fluvialis- II was determined by using drugpaper to inhibit proliferation of the bacteria and then the diameter of the ring for bacteria inhibiton was meatured. The results showed that different strains have different sensitivity. The D strain (isolated from the diseased abalone of the Aquacultural Company of Dalian) was sensitive to Ciprofloxacin [the diameter of ring for bacteria inhibition (DRBI) was 30.0 mm], Cotrimoxazole (DRBI was 27.0 mm), Furazo lidone (DRBI) was 26.0 mm), Nor?oxacin (DRBI was 25.0 mm), and Chloramphenicol (DRBI was 20.0 mm), Gentamycin (DRBI was (20.0 mm), Erythromycin (DRBI was 20.0 mm); and resistant to Ampicillin, Penicillin and Cephalosporin (DRBI was 0 mm), The N strain (isolated from the diseased abalone of the New Harbor Aquacultrual Company of Dalian) was sensitive and moderately sensitive to the 12 kinds of antibiotics, including Chloramphenicol (DRBI was 30.0 mm), Cotrimoxazole (DRBI was 25.5 mm), Cipro?oxacin (DRBI was 21.5 mm), Nor?oxacin (DRBI was 20.0 mm), Gentamicin (DRBI was 19.0 mm), Furazo lidone (DRBI was 19.0 mm): and resistant to Cefoperazone, Streptomycin, Cephalosporin, Leucomycin, Pipemidic Acid and Penicillin II. The Tstrain (isolated from the diseased abalone of the Pacific Aquacultural Company) was sensitive to Nor?oxacin (DRBI was 22.0 mm), Cipro?oxacin (DRBI was 20.3 mm), Gentamicin (DRBI was 19.3 mm), Penicillin (DRBI was 19.3 mm), Erythromycin (DRBI was 18.7 mm); and resistant to Cotrimoxaxole, Chloramlphenicol, Methacycline (DRBI was 0 mm). The MIC and MBC test of the T strain was performed by using 9 kinds of antibiotics dilution The results showed that for Ciprofloxacin MIC was 0.31 μg/ml, MBC was 0.63 μg/ml; for Ampicillin MIC was 0.78 μg/ml, MBC was 1.56 μg/ml; for Penicillin MIC was 1.25 μg/ml, MBC was 2.5 μg/ml; for Gentamicin MIC was 3.12 μg/ml, MBC was 6.25 μg/ml; for Furazo lidone MIC was 3.12 μg/ml, MBC was 6.25 μg/ml; for Erythromycin MIC was 6.25 μg/ml, MBC was 12.5 μg/ml. The sensitivity was changed along with the transparency of the bacteria colony by treatment of the diseased abalone with Penicillin for 11 days. The mechanism of resistance of V. fluvialis-II was studied by gene engineering. The total DNA of the three strains was extracted and digested by Restriction Enzymes EcoR I . Electrophoresis showed that the three strains had many different bands.
The above results suggested that the mechanism of resistance of V. fluvialis-II was related to gene mutation, and that antibiotics provided necessary condition for the bacteria resistance. |
| Key words: Haliotis discus Hannai, Vibrio fluvialis- II, Pustule disease, Mechanism of resistance to antibiotics |
