微生物聚集体形态对多重耐药质粒接合转移的影响  

INFLUENCE OF MICROBIAL AGGREGATES MORPHOLOGY ON CONJUGATION OF ANTIBIOTIC-MULTIRESISTANT PLASMID RP4

作　　者：智维佳 杨栋[1] 张斌[1] 邱志刚[1] 薛斌[1] 王雪[1] 李君文[1] 王景峰[1] 

机构地区：[1]军事医学科学院卫生学环境医学研究所,天津300050

出　　处：《解放军预防医学杂志》2015年第4期364-367,共4页Journal of Preventive Medicine of Chinese People's Liberation Army

摘　　要：目的研究水污染控制系统中微生物聚集体形态对多重耐药质粒接合转移的影响，为控制耐药基因在水环境中的传播提供科学依据。方法向运行稳定的颗粒污泥序批式反应器（ granu-lar sequencing batch reactor, GSBR） 中投加具有利福平抗性且携带RP4质粒的大肠杆菌K12[E．coliK12（RP4）Rif]，将系统中的污泥按照粒径划分为4个区间，分别用定量PCR方法对污泥中总细菌16SrDNA和耐药质粒RP4进行定量，从而得到不同粒径区间的接合转移比例：同时监测GSBR中NH4＋-N、CODcr的去除效率和污泥浓度（MLSS），以评价GSBR运行效能。结果投加供体菌后，系统中的供体菌所占比例在2d内出现急剧下降，此后3～5d，RP4所占比例一直稳定在10^-7～10^-6。从投加供体菌的第7天开始，粒径大于0．9mm的微生物聚集体中无法检测出RP4：粒径范围在0．18—0．45mm、0．46～0．9mm的微生物聚集体中的RP4质粒在投加后的第11天消失：而粒径小于0．18mm的絮状污泥中的RP4在投加供体菌后第19天消失。RP4在不同粒径微生物聚集体中的接合转移率明显不同，随 着粒径的增大而降低。系统中投加供体菌后CODcr、NH4＋-N的去除率均明显下降；污泥浓度（MLSS）从4855mg／L降至3168mg／L。结论实验过程中微生物聚集体的形态对耐药质粒RP4的接合转移有明显影响，粒径越大其接合转移率越低；且在投加供体菌初期，反应器NH4＋-N、CODcr的去除能力下降明显，供体菌的投加也使污泥浓度的MLSS下降。Objective To investigate the influence of microbial aggregates morphology on conjugal trans- fer of antibiotic-muhiresistance plasmid in the microbial water pollution control system, so as to provide a scientific basis to control the spread of antibiotic resistance genes. Methods The E. coli K12 （RP4）Rif was added into the stable-operated reactor. The microbial aggregates was sampled and divided into four ranges according to the parti- cle diameter, then real time quantitative PCR was applied to quantify the total bacterial 16S rDNA and the plasmid RP4, thus the conjugal transfer efficiency of multi-resistant plasmid among different diameter microbial aggregates was obtained. The removal efficiency of NH4＋-N, CODcr and mixed liquid suspended solid（MISS） was measured simultaneously to evaluate the performance of the system. Results After the donor strain was inoculated, the amount of E. coli K12（RP4） Rif in the system dropped sharply in 2 days, while on day 3 -5 the amount of RP4 remained at 10^-7 to 10^-6. From day 7, the amount of RP4 in microbial aggregates larger than 0.9mm was undetectable, while the RP4 plasmid disappeared on day 11 in microbial aggregates with daimeter 0.46 to 0.9 mm or 0.18 to 0.45 mm, and on day 19 in microbial aggregates with daimeter 〈0.18 mm. Obviously, the conjugal transfer efficiency between the donor strain and the microbial aggregates in different diameters presented a distinct difference, it de- creased with the increase of the diameter. After inoculation, the average removal efficiency of NH4＋-N and CODcr significantly decreased, at the same time, the MISS declined from 4855 mg/L to 3168 mg/L. Conclusions The morphology of microbial aggregates can influence the conjugation of antibiotic-muhiresistance plasmid RP4, the lar- ger the diameters are, and the lower the conjugal transfer efficiency it has. The donor strain inoculation can de- crease the removal efficiency of NH4＋ -N and CODcr in the system. MISS has a descended trend with the donor strain inoculation

关 键 词：多重耐药质粒 微生物聚集体形态 接合转移 

分 类 号：TU991.2[建筑科学—市政工程]