成都平原不同种植方式折耳根表面附生细菌群落结构与抗生素抗性基因分析

Bacterial community structure and antibiotic resistance gene on the surface of Houttuynia cordata Thunb from different planting patterns in Chengdu plain

【目的】分析有机、化肥和野生折耳根表面的附生细菌群落结构和抗生素抗性基因(ARGs),揭示细菌群落结构与ARGs相互关系。【方法】高通量测定16SrRNAV3-V4可变区序列分析样品表面附生细菌群落结构;PCR和qPCR扩增29种ARGs基因分析样品表面ARGs污染情况;冗余分析(RDA)探讨细菌群落结构与ARGs的相互关系。【结果】折耳根表面检测到35个属的细菌,其中有机折耳根表面附生细菌多样性低于化肥和野生折耳根(P<0.05);29种被检的ARGs中,有14种在折耳根中被检出,其中有机折耳根含有全部被检出的ARGs,化肥和野生折耳根则含有部分被检出的ARGs。折耳根表面ARGs污染的多样性和丰度显著受到样品表面的菌群结构影响,其中Lactococcus、 Escherichia、Fluviicola、Enterococcus、Sanguibacter和Acidovorax是影响ARGs最主要的菌群。【结论】有机种植极大地改变了折耳根表面附生细菌的群落结构,增加了ARGs的多样性和丰度,对有机折耳根的食品安全带来了潜在威胁。因此,有必要将ARGs污染监测纳入到有机折耳根的食品安全考核范围内。

[Objective]The aim of this study is to analyze bacterial community and antibiotic resistant genes(ARGs)in organic,fertilized and wild Houttuynia cordata Thunb,and to reveal the relationship between bacterial community and ARGs.[Methods]The bacterial community structure was investigated by high-throughput 16S rRNA V3-V4 variable region sequencing.The qualitative and quantitative analysis of 29 ARGs was determined by PCR and qPCR.The redundancy analysis was used to reveal the relationship between bacterial community and ARGs.[Results]A total of 35 genera of bacteria were detected.The bacterial diversity in organic H.cordata Thunb was lower than that in fertilized and wild H.cordata Thunb.Fourteen ARGs were detected on H.cordata Thunb.All detected ARGs were found in the organic H.cordata Thunb,while only part was found in the fertilized and wild H.cordata Thunb.Redundancy analysis showed ARGs were significantly affected by bacterial diversity and abundance,and Lactococcus,Escherichia,Fluviicola,Enterococcus,Sanguibacter and Acidovorax were main bacteria which affected on the diversity and abundance of ARGs on H.cordata Thunb.[Conclusion]Organic planting affects bacterial community on H.Cordata Thunb,and increases diversity and abundance of ARGs,suggesting a potential food safety risk.Therefore,it is necessary to bring ARGs contamination into the scope of food safety assessment for organic H.cordata Thunb.