北京市售生食果蔬中耐药基因赋存特征及迁移风险

Characterization and transfer risk of antibiotic resistance genes from commercially raw vegetables and fruits in Beijing

中文关键词:  生食果蔬  耐药基因  迁移风险  可移动遗传元件  高通量定量PCR

英文关键词:raw vegetables and fruits  antibiotic resisitance genes (ARGs)  transfer risk  mobile genetic elements (MGEs)  high-throughput quantitative PCR (HT-qPCR)

中文摘要:

      目的 通过调研抗生素耐药基因(antibiotic resistance genes, ARGs)的赋存特征,探讨其在食品安全领域的潜在风险。方法 采用高通量定量PCR(high-throughput quantitative PCR, HT-qPCR)技术,对北京市售生食果蔬中ARGs及可移动遗传元件(mobile genetic elements, MGEs)的多样性和存在丰度进行描述,并通过高风险筛查、相关性分析、冗余分析、方差分解分析,探讨ARGs的迁移风险。结果 共检出9大类188个ARGs和9个MGEs,丰度范围分别为6.18x10₃^~1.24x10₈ copies/g、5.86x10₃^?~?3.34x10₈ copies/g；四环素类、氨基糖苷类、β-内酰胺类、大环内酯-林可霉素-链阳霉素类(macrolide-lincosamide-streptogramin B, MLSB)ARGs分布最广；多重耐药类ARGs丰度最高；涉及的主要耐药机制贡献大小为抗生素灭活>外排泵>细胞保护。其中,Lb(苦菊)的ARGs检出率最高,Sg(青椒)的ARGs丰度最高；茄果类、叶菜类ARGs丰度普遍高于根茎类蔬菜；水果类样品中ARGs的检出率和丰度最低。果蔬样品中高风险ARGs普遍存在,丰度最高可达7.85x10₇ copies/g；氨基糖苷类、磺胺类、四环素类、多重耐药类ARGs具有高迁移风险,整合酶和转座酶两类转移机制共同构成主要驱动因素(46.44%)。结论 本文揭示了生食果蔬中ARGs赋存情况严重,具有较高的迁移风险,很可能导致耐药现象的大量产生及扩散,危害人类健康,应引起高度重视。

英文摘要:

      Objective This study aims at investigating the characterzation of antibiotic resistance genes (ARGs), and exploring their potential food safety risks. Methods In this study, the diversity and abundance of antibiotic resisitance genes and mobile genetic elements (MGEs) from commercially raw vegetables and fruits in Beijing, were detected using high-throughput quantitative PCR (HT-qPCR). And the transfer risk was explored by sorting out high-risk antibiotic resisitance genes, constructing correlation matrixes, redundancy analysis, and variance partitioning analysis. Results A total of 188 antibiotic resistance gene subtypes belonging to 9 antibiotic types and 9 MGE subtypes were detected with the abundance 6.18x10₃^~1.24x10₈ copies/g and 5.86x10₃^~3.34x10₈ copies/g, respectively; tetracycline, aminoglycoside, β-lactamase, macrolide-lincosamide-streptogramin B (MLSB) resistance genes had the most wide occurrence range; multidrug resistance genes had the highest abundance; the contribution of key gene resistance mechanisms was as follows: antibiotic deactivation > efflux pump > cellular protection. The abundance of ARGs in solanaceae and leaf vegetables was generally higher than that of root vegetables, and the detectable rate and abundance of ARGs in fruit samples was the lowest of all, with the highest detectable rate and abundance of ARGs in Lb (bitter chrysanthemum) and Sg (green pepper), respectively. High-risk ARGs were prevalent in samples, with 7.85x10₇ copies/g; the transfer risk of aminoglycoside, sulfonamide, tetracycline and multidrug resistance genes was generally high, and the combination of integrase and transposase was the key driving force (46.44%). Conclusion The results revealed that ARGs from raw vegetables and fruits have a serious characterization, with high transfer risk, which could lead to the emergence and spreading of antibiotic resistance and threaten human health. So high attention should be attached.