| 4. Temperature has a significant effect on the adhesion ofresistanceE. coli, At (10℃) low temperature conditions, theadhesion capacity of multi-drug resistant E. coliare all weak, drawing a conclusion that low temperature and conditions are not conducive to adhesion of multi-drug resistant E. colito silica particles; with high temperature, some bacteria adhered more under 20 ℃, while others exhibit greater adhesive capacity at 35℃.5. The same adhesion ability of E. coli cases in different antibiotics culture also have significant differences. Under antibiotic stimulation, some E. coli weaker adhesion, show more migration, proliferation trend, as the water flows easily result in higher security risks in an aqueous environment.6. DLVO theory predicts hydrophobic interactions in ionic strength 1-300 mM was found to be dependent on the separation distance. While at high ionic strength, interaction between the particles are all potential energy gravitational potential energy, very favorable for bacterial adhesion, which is inconsistent with the actual experiments illustrate DLVO theory can not fully explain the phenomenon of adhesion.Currently, a large number of studies have shown that the excessive use of antibiotics make the environment bacterial pathogens become resistant.Resistant bacteria can infect humans through drinking water, aquatic products and direct contact,which accelerate pathogen resistance genes to get the chance to increase the difficulty of treatment of infectious diseases. The change of multidrug-resistant Escherichia coli in surface characteristics of different antibiotic stimulation largely determines the spread of these resistant bacteria proliferation capacity in an aqueous environment and their environmental risks. Most previous studies showed the ordinary culture medium for bacteria adhesion kinetics, but the bacterial surface composition and structure of biological macromolecules vary with different antibiotics stimulate, resulting in an impact on adhesion and migration processes.This paper chose LB medium for multidrug-resistant Escherichia CLSS 5,6,8 for the research.Under different antibiotic stimulation exhibited by surface features,there aredifferen.conditions.Otherwise,with different ionic strength of the particles in water, theysuspended in quartz sand have special adhesion and transfer law.Combined with DLVO theoretical calculations,there is a more accurate assessment of multi-drug resistant E. coli security risk to the water environment.In this study, the conclusions are as follows:1.Under the same culture conditions, the zeta potential ofE.coli CLSS 5,6,8 reacted with different antibiotics conditions were increases with increasing ionic strength.And different antibiotics stimulate made the zeta potential varies greatly. At the same ionic strength, after the bacteria cultured in medium containing antibiotics, zeta potential values were significantly lower to the range of 15 mV-5 mV. It reflects the different conditions of surface properties of these bacteria with different stimulus of antibiotics.2. In the no antibiotics culture conditions,thehydrophobicity of E.coli CLSS 5,6,8 were lower than 20%. In the contrast, hydrophobic trends of different bacteria with antibiotics culture significantly differ from the normal condition.3. Ionic strength has asignificant impact on the adhesion of multi-drug resistant E. coli. For the same conditions, with the increase in ionic strength exhibit a significant changeof the adhesion of silica particles. For the E.coli CLSS 5 and E.coli CLSS 6, under the same experimental temperature, the number of adherent bacteria with increasing ionic strength are increase at the first,reaching the maximum at 10 mM, then decrease gradually. However,E.coli CLSS 8 has a different performance:the trends are not only like the others but also continuing increase, the number of bacteria adhered ranges from 108～109/mg. |
PDF Full Text Request