养殖废水中抗生素与重金属交叉抗性微生物的筛选及其抗性研究

Screening on Resistance Strains of Antibiotic and Heavy Metal from Breeding Wastewater and Its Resistance Research

为了探索废水中具有抗生素和重金属交叉抗性的微生物的抗性机制以及抗性微生物的种类,直接从含养殖场废水的选择培养基中分离菌种,通过设计试验,观察其在含有重金属(Pb2+:33.33mg/L,Cr6+:34.67mg/L,Hg2+:16.67mg/L,Cu2+:33.33mg/L)和抗生素(阿莫西林A:3.33mg/L,诺氟沙星N:2.67mg/L,头孢拉定C:4.17mg/L)的二元交叉培养基上的生长情况。结果表明:分离得到的7株菌中,4株为G-杆菌,3株为G+杆菌。所有二元交叉培养基上均有抗性菌生长,G-菌的抗性明显强于G+菌,其中1#菌具有六重交叉抗性(Pb+A、Cr+N、Hg+N、Hg+C、Cu+A、Cu+C),4#和7#菌均只具有一重交叉抗性,分别为Cu+N和Cr+C,具有Hg+N交叉抗性的菌最多有4株,而具有Cr+N、Pb+C、Cu+C或Cr+C交叉抗性的菌均只有1株,菌种对抗生素的抗性强于对重金属的抗性。因此,养殖废水排放可能引发抗生素和重金属交叉抗性微生物的公众健康危害。

In order to explore the mechanism and species of microorganism,which was from wastewater and had possessed cross-resistance of heavy metals and antibiotic,bacteria were isolated from the selective culture mediums prepared by breeding wastewater,and based on the experimental design,their characteristics growing on the K-B agar mediums containing the heavy metals （33.33 mg/L Pb 2 ＋,34.67 mg/L Cr 6 ＋,16.67 mg/L Hg 2 ＋,33.33 mg/L Cu 2 ＋） and the drug sensitivity papers （3.33 mg/L Amoxicillin,2.67 mg/L Norfloxacin,4.17 mg/L Cefradine） were observed.7 strains were isolated from the breeding wastewater,and the numbers of rod-shaped Gram-positive and Gram-negative bacteria were 3 and 4,respectively.The resistance of the Gram-negative bacteria was stronger than the Gram positive bacteria.In which,strain 1# had 6 kinds of cross resistance （Pb＋A,Cr＋N,Hg＋N,Hg＋C,Cu＋A,Cu＋C）,while both strain 4# and 7# had only one kind of cross resistance to Cu＋N and Cr＋C,respectively.4 strains could grow on the culture medium containing Hg＋N,and only one strain could grow on the culture medium containing Cr＋N,Pb＋C,Cu＋C or Cr＋C.The results of the cross resistance experiments also showed that the resistance of 7 strains to antibiotics was stronger than those to heavy metals.Therefore,a potential risk for public health due to discharge of the breeding wastewater might caused by the microorganism with cross resistance to heavy metals and antibiotics.