Department of Microbiology, Periyar University, Salem, Tamil Nadu, India.
Department of Biotechnology, Periyar University, Salem, Tamil Nadu, India.
Biomed Res Int. 2018 May 16;2018:1535209. doi: 10.1155/2018/1535209. eCollection 2018.
Pesticide residual persistence in agriculture soil selectively increases the pesticide-degrading population and transfers the pesticide-degrading gene to other populations, leading to cross-resistance to a wide range of antibiotics. The enzymes that degrade pesticides can also catabolize the antibiotics by inducing changes in the gene or protein structure through induced mutations. The present work focuses on the pesticide-degrading bacteria isolated from an agricultural field that develop cross-resistance to antibiotics. This cross-resistance is developed through catabolic gene clusters present in an extrachromosomal plasmid. A larger plasmid (236.7 Kbp) isolated from sp. was sequenced by next-generation sequencing, and important features such as - hydrolase, DNA topoisomerase, DNA polymerase III subunit beta, reverse transcriptase, plasmid replication rep X, recombination U, transposase, and S-formylglutathione hydrolase were found in this plasmid. Among these, the - hydrolase enzyme is known for the degradation of organophosphate pesticides. The cloning and expression of the - hydrolase gene imply nonspecific cleavage of antibiotics through a cross-resistance phenomenon in the host. The docking of - hydrolase with a spectrum of antibiotics showed a high G-score against chloramphenicol (-3.793), streptomycin (-2.865), cefotaxime (-5.885), ampicillin (-4.316), and tetracycline (-3.972). This study concludes that continuous exposure to pesticide residues may lead to the emergence of multidrug-resistant strains among the wild microbial flora.
农药残留会在农业土壤中选择性地增加农药降解菌的数量,并将农药降解基因转移到其他种群中,导致对广泛的抗生素产生交叉耐药性。降解农药的酶也可以通过诱导基因突变来改变基因或蛋白质结构,从而代谢抗生素。本工作重点研究了从农田中分离出的对农药具有交叉耐药性的降解细菌。这种交叉耐药性是通过存在于染色体外质粒中的降解基因簇发展起来的。从 sp. 中分离出的一个较大的质粒(236.7 Kbp)通过下一代测序进行了测序,并在该质粒中发现了重要特征,如 - 水解酶、DNA 拓扑异构酶、DNA 聚合酶 III 亚基β、逆转录酶、质粒复制 rep X、重组 U、转座酶和 S-甲酰谷胱甘肽水解酶。其中,- 水解酶酶已知可降解有机磷农药。- 水解酶基因的克隆和表达暗示了通过宿主中的交叉耐药现象对抗生素进行非特异性切割。- 水解酶与一系列抗生素的对接显示对氯霉素(-3.793)、链霉素(-2.865)、头孢噻肟(-5.885)、氨苄西林(-4.316)和四环素(-3.972)具有高 G 评分。本研究得出结论,持续接触农药残留可能导致野生微生物菌群中出现多药耐药菌株。