Antibiotic-resistant. soil bacteria in transigenic plant fields
Antibiotic-resistant. soil bacteria in transigenic plant fields
复制标题
DOI：
10.1073/pnas.0800072105
复制
发表时间：
2008-03-11
影响因子：
11.1
通讯作者：
Simonet, Pascal
中科院分区：
文献类型：
--
作者：
Demaneche, Sandrine;Sanguin, Herve;Simonet, Pascal
了解土壤细菌中抗生素耐药基因的患病率和多态性及其水平转移的潜力是评估这些基因从转基因植物转移到土壤细菌的可能性和生态（以及可能的临床）后果所必需的。在本研究中，我们采用培养依赖和独立相结合的方法，研究了bla基因在土壤细菌中的流行度和多样性，以及连续110年培养含有b/aTEM标记基因的转基因Bt176玉米对土壤细菌群落的潜在影响。编码氨苄西林耐药性的bla基因属于β -内酰胺类抗生素家族，该基因广泛用于医学，但很容易被细菌抗生素耐药性所破坏。我们的研究结果表明，土壤细菌对广谱的β -内酰胺类抗生素具有天然抗性，包括第三代头孢菌素，其对土壤分离物的鉴别作用略强于其他头孢菌素。这些对多种抗生素的高耐药水平部分是由于bla基因的多态性，这在土壤细菌中经常发生。本文研究的转基因玉米Bt176的b/aTEM1 16基因是经常发现的基因之一，因此降低了从转基因材料引入新的细菌抗性性状的风险。此外，转基因玉米和非转基因玉米的细菌耐药水平没有显著差异，尽管细菌群体不同。
Understanding the prevalence and polymorphism of antibiotic resistance genes in soil bacteria and their potential to be transferred horizontally is required to evaluate the likelihood and ecological (and possibly clinical) consequences of the transfer of these genes from transgenic plants to soil bacteria. In this study, we combined culture-dependent and -independent approaches to study the prevalence and diversity of bla genes in soil bacteria and the potential impact that a 110-successive-year culture of the transgenic Bt176 corn, which has a b/aTEM marker gene, could have had on the soil bacterial community. The bla gene encoding resistance to ampicillin belongs to the beta-lactam antibiotic family, which is widely used in medicine but is readily compromised by bacterial antibiotic resistance. Our results indicate that soil bacteria are naturally resistant to a broad spectrum of beta-lactam antibiotics, including the third cephalosporin generation, which has a slightly stronger discriminating effect on soil isolates than other cephalosporins. These high resistance levels for a wide range of antibiotics are partly due to the polymorphism of bla genes, which occur frequently among soil bacteria. The b/aTEM1 16 gene of the transgenic corn Bt176 investigated here is among those frequently found, thus reducing any risk of introducing a new bacterial resistance trait from the transgenic material. in addition, no significant differences were observed in bacterial antibiotic-resistance levels between transgenic and nontransgenic corn fields, although the bacterial populations were different.