Survival of enterococci and Tn916-like conjugative transposons in soil
Survival of enterococci and Tn916-like conjugative transposons in soil
复制标题
DOI：
10.1139/w04-090
复制
发表时间：
2004-11-01
影响因子：
2.8
通讯作者：
Marvin, JD
中科院分区：
文献类型：
--
作者：
Andrews, RE;Johnson, WS;Marvin, JD
将粪肠球菌、来自猪粪便的粪肠球菌和tn916样元素接种于高压灭菌和原生土壤微生物中，测定其持久性。将粪肠球菌CG110 （Tn916）细胞接种到天然微生物中，5周后，土壤中的肠球菌活力下降了约5个数量级（4.8 × 10(5) CFU/g土壤至< 10 CFU/g）。在高压灭菌的微环境中，5周内粪肠杆菌的存活率仅下降了20%。相比之下，土壤微生物中Tn916的含量，基于DNA提取的PCR，在原生和高压灭菌的微生物中，Tn916的含量都下降了约20%。当粪肠球菌和tn916样元素的来源为猪粪时，也得到了类似的结果。由于基于PCR的不依赖Tn916的粪肠杆菌DNA （d -丙氨酸d -丙氨酸连接酶基因）的浓度在原生微生物环境中5周后下降到几乎无法检测到的水平（至少3个数数级），有证据表明Tn916在土壤中的稳定性是由于转座子大量转移到正常土壤微生物群中，而不是粪肠杆菌DNA在土壤系统中的存活。变性梯度凝胶电泳结果表明，猪粪中存在多种形式的Tn916，但只有最像Tn916的形式在土壤中表现出稳定性。
The persistence of Enterococcus faecalis, fecal enterococci from swine waste, and Tn916-like elements was determined following inoculation into autoclaved and native soil microcosms. When cells of E. faecalis CG110 (Tn916) were inoculated into native microcosms, enterococcal viability in the soil decreased approximately 5 orders of magnitude (4.8 x 10(5) CFU/g soil to < 10 CFU/g) after 5 weeks. In autoclaved microcosms, the viability of E. faecalis decreased by only 20% in 5 weeks. In contrast, the content of Tn916, based on PCR of DNA extracts from soil microcosms, decreased by about 20% in both native and autoclaved microcosms. Similar results were obtained when the source of fecal enterococci and Tn916-like elements was swine waste. Because the concentration of Tn916-independent E. faecalis DNA (the D-alanine D-alanine ligase gene), based on PCR, decreased to nearly undetectable levels (at least 3 orders of magnitude) after 5 weeks in the native microcosms, the evidence suggests Tn916 stability in the soil results from en masse transfer of the transposon to the normal soil microflora and not survival of E. faecalis DNA in the soil system. Results from denaturing gradient gel electrophoresis suggest that multiple forms of Tn916 occur in swine waste, but only forms most like Tn916 exhibit stability in the soil.