Antibiotic-resistant soil bacteria in transgenic plant fields

Area of Science:

• Environmental microbiology
• Molecular biology
• Agricultural science

Background:

• Antibiotic resistance genes (ARGs) in soil bacteria pose ecological and clinical risks.
• Horizontal gene transfer (HGT) from transgenic plants to bacteria is a concern.
• The bla gene confers resistance to beta-lactam antibiotics, crucial in medicine.

Purpose of the Study:

• To investigate the prevalence and diversity of bla genes in soil bacteria.
• To assess the impact of transgenic Bt176 corn cultivation on soil bacterial antibiotic resistance.
• To evaluate the risk of introducing new resistance traits from transgenic materials.

Main Methods:

• Combined culture-dependent and culture-independent approaches.
• Analysis of bla gene prevalence and polymorphism in soil bacteria.
• Comparison of antibiotic resistance levels in soil from transgenic and non-transgenic corn fields.

Main Results:

• Soil bacteria naturally possess high resistance to a broad spectrum of beta-lactam antibiotics.
• High polymorphism of bla genes contributes to widespread antibiotic resistance in soil bacteria.
• The blaTEM116 gene in Bt176 corn is common in soil bacteria, minimizing introduction risk.
• No significant difference in bacterial antibiotic resistance between transgenic and non-transgenic corn fields was observed.

Conclusions:

• Soil bacterial communities exhibit inherent, diverse resistance to beta-lactam antibiotics.
• Cultivation of Bt176 corn did not enhance the prevalence of bla genes in soil.
• The risk of HGT of bla genes from this transgenic corn to soil bacteria is low due to natural prevalence.