Antibiotic Contaminated Soil Bacterial Ecology And Its Resistance

At present, the choice pressures caused by antibiotics cause the increase of the antibiotic resistance and the diversification in resistant bacteria and resistant mechanism, they are severe test to human antiinfection treatment. On the other hand, pharmaceutical wastewater and medical wastewater containing antibiotics pharmaceutical are discharged into environment. As Well as agricultural use of livestock excreta containing a large number of antibiotics,which directly cause the damage of environmental microbial ecosystem. Meanwhile because of the long-term antibiotic residues may cause Microbial resistance changes in the environment such as soil environment.In this paper, the integrated use of traditional methods of microbial ecology , molecular biology research means and methods of clinical medicine, the impact on microbial ecology have been analyzed when antibiotics into the soil environment. In addition, the resistance status of microorganisms, the resistance mechanism was also discussed. The results are as follows:1, Adding the different concentrations of cefotaxime (CTX)into the soil, dynamic analysises of biological activity were applied ,the results showed that: in a period of time, the effects of CTX on respiration, urease, catalase and the number of bacteria are certain to boost performance role. the soil of Cowhouse, farmland, lawn polluted by antibiotics,they were diluted and counted with different concentrations of streptomycin (S), penicillin (P), cefotaxime (CTX) of culture plates, the strongest resistance of soil bacteria was found in cowhouse soil, and the number of bacteria have increased significantly than the control in a certain concentrations antibiotics of medium.2, During the DGGE analysis, we found there are many differences of soil bacteria diversity between the soil of long-term use of cow dung containing antibiotics and no cow dung application soil. But the soil samples of short-term deal with the use of CTX, bacterial community diversities had little changes with the processing time,wich means as the long-term sustainability of antibiotics polluted, the soil microbial community structure had been significantiy changed, but short-term antibiotics imposed on the soil, the microbial community structure had no significant effect. May be they can withstand a certain degree of antibiotic pressure in the soil microbial ecosystems.3, The bacteria isolated from the soil of long-term antibiotics continued pollution, their antibacterial spectrum analysis showed that: among the detection of the strain, with the multi-drug resistance of 44.44 percent, with production ofβ-lactamase of 39.67 percent, many of them are highly resistant. During the experiment, five ESBLs-producing strains were detected. Through sequencing, homology analysis, and evolutionary tree construction, the five strains have highly similar sequences with strong resistance of bacteria reported in the relevant literatures.