畜禽养殖环境中抗生素抗性基因污染的研究进展

畜禽养殖中抗生素不当使用导致的抗生素抗性基因(ARGs)污染问题日益严重,引起了国际社会的广泛关注。养殖环境中的ARGs不但可通过吸附、解吸、迁移等途径发生跨介质扩散,也可通过水平基因转移(HGT)使耐药性跨菌属传播,甚至通过食物链传递给人类,对公众健康造成潜在威胁。然而,目前缺少以大健康视角总结分析畜禽养殖环境ARGs赋存特征、关键环境过程和阻控技术的研究,导致对ARGs传播风险的评估和污染阻控对策的制定难以有效开展。本文在分析不同国家、畜种、环境介质中ARGs污染水平差异的基础上,阐述了ARGs在畜禽养殖环境中的关键环境过程和主要影响因素,重点论述了当前畜禽养殖业ARGs的污染阻控技术,最后结合大健康的方法理念,指出了目前研究存在的不足和亟需加强的方面,尤其强调了明确ARGs时空演变规律和环境过程机制、开发绿色高效的污染阻控技术的重要性与紧迫性,以期为畜禽养殖环境中ARGs健康风险评估和污染阻控技术的开发提供理论依据。     

不同环境介质中抗生素耐药性的检测方法研究进展

抗生素在医疗和畜禽养殖业的大量使用增加了环境中抗生素抗性微生物(ARB)和抗性基因(ARGs)的丰度与多样性,加速了抗生素耐药性在环境中的传播,给人类公共健康造成潜在威胁。但目前对于环境中耐药性的污染现状缺少足够的信息,相关研究方法亟待优化和完善。本文通过综述环境中抗生素耐药性的国内外研究现状,探讨了不同环境(水、土壤、空气等)样品的采集方法以及耐药性的检测方法——传统微生物培养法和分子生物学方法(如定性与定量PCR、DNA杂交及微阵列技术、宏基因组学方法等),旨在为多环境介质中抗生素耐药性的研究提供科学依据和技术支持。     

污水处理厂中四环素和磺胺类抗生素抗性基因的分布、传播及去除

近年来,抗生素滥用造成的抗性基因(ARGs)污染问题引起了人们的关注.四环素及磺胺类抗生素由于价格低廉被广泛使用,大量残留的四环素和磺胺通过各种途径进入污水处理厂,并进一步导致ARGs的污染.为深入了解四环素和磺胺类ARGs的污染及治理现状,本研究对污水处理厂中四环素和磺胺类ARGs的分布情况及传播机制进行了综述,并重点讨论了不同污水处理工艺对ARGs的去除效果.在此基础上,从加大污水处理厂ARGs污染调查、改进污水处理工艺以及探讨ARGs传播机制等方面进行了展望.     

环境中胞内胞外抗性基因的分离检测、分布与传播

抗生素抗性基因(ARGs)传播对人类健康具有潜在的风险。胞内抗性基因(iARGs)和胞外抗性基因(eARGs)是抗生素抗性基因的两种存在形式,其在不同环境介质中的分布与传播过程具有截然不同的特征。本文首先基于ARGs赋存形态的差异,对染色体抗性基因、质粒抗性基因、噬菌体抗性基因等ARGs的胞内/胞外分类给予明确界定,并根据环境样品来源归纳了现有分离检测技术的应用场景,总结了iARGs和eARGs在养殖场、污水处理厂、河道、海洋、大气等环境中的分布特征,同时比较了其在传播方式和传播能力上的差异,以期为ARGs的分类阻控和健康风险评估提供理论参考。     

水平基因转移介导抗菌素耐药性传播机制的研究进展

近几十年来,病原菌耐药性的出现和蔓延已上升为严峻的公共卫生问题。越来越多研究表明,抗菌素抗性基因(antibiotic resistance genes,ARGs)不仅仅见于临床所分离的病原体,而是包括所有的致病菌、共生菌以及环境中的细菌,它们都能在可移动遗传元件和噬菌体的作用下,通过水平基因转移(horizontal gene transfer,HGT)途径获得耐药性,进而形成抗菌素耐药基因簇(耐药基因组)。HGT可导致抗菌素的耐药性在环境共生菌和病原菌之间传播扩散,这可通过临床上一些重要的抗菌素耐药基因的传播证实。传统观念认为HGT的三种机制中,接合对ARGs的传播影响最大,最近研究表明转化和转导对ARGs播散起到不可忽视的作用。通过深入了解耐药基因组的传播及其在动员病原菌耐药中发挥的作用,对于控制这些基因的播散是至关重要的。将讨论耐药基因组的概念,提供临床相关的抗菌素抗性基因水平基因转移的例子,对当前已研究的促使抗菌素耐药性传播的各种HGT机制进行回顾。     

气溶胶中抗生素抗性基因研究进展

抗生素的不合理使用导致细菌耐药问题日趋严峻,给人类健康造成巨大威胁。学者们对抗生素抗性菌和抗生素抗性基因(antibiotic resistance genes, ARGs)在多种环境介质中的环境行为开展了大量研究。气溶胶作为ARGs的潜在储存库,是抗生素抗性基因在环境中的重要传播途径之一。目前缺乏对其来源、传播、人类接触和健康风险系统性的梳理。本文针对人类生活功能场所、养殖场、城市污水处理厂和医院等4类气溶胶研究的典型场所,重点综述了上述4类典型场所中气溶胶ARGs的来源、传播途径及对人体的暴露和对健康的危害,为气溶胶中ARGs的预防和控制提供参考。     

新型抗生素抗性基因传播元件ISCR及其生态风险

抗生素抗性基因(antibiotic resistance genes, ARGs)作为一种新型的环境污染物,成为多个学科关注的焦点.其在不同环境介质中的扩散和传播具有极大的环境危害性,对人类健康造成严重威胁.插入序列共同区(insertion sequence common region, ISCR),是一种新发现的抗性基因传播元件,因其特殊的遗传结构,能够通过滚环复制及同源重组等机制移动邻近的任何DNA序列,是ARGs在不同DNA分子或不同种属细菌间水平传播的高效媒介.目前世界上发现了27种ISCR元件.大量间接证据表明,ISCR可能与许多耐药基因的移动和扩散有关,特别是多重耐药性(multiple drug resistance, MDR)形成与传播.因此,ISCR很可能是抗生素抗性基因在环境中扩散传播的关键因子.本文就ARGs水平传播、ISCR结构特征、ISCR种类及其相关ARGs及其研究方法等进行综述,并揭示ISCR元件可能的生态风险,提出了今后的研究重点,以期为今后深入开展相关研究打下基础.     

抗生素抗性基因的生态风险研究进展

自抗生素被发现和使用以来,其在人类和动物疾病预防与治疗、提高动物生产等方面均发挥了重要作用。但抗生素的批量生产及大量应用,特别是在养殖业和临床医疗上的滥用,导致抗生素抗性基因(ARGs)在环境中普遍存在,其借助质粒、转座子、整合子等可移动元件通过接合、转座、转化等方式在环境中广泛传播,导致微生物药性不断增强,对人类健康和生态安全造成严重威胁。当前,ARGs对人类健康的影响已受到高度关注,但有关ARGs在环境中的生态风险研究还相对薄弱。本文综述了ARGs污染的现状及其生态风险,并对该领域中未来研究重点进行了展望,以期为今后抗性基因的研究和生态防控提供参考。     

用两步MS-PCR结合ELISA检测HIV-1逆转录酶基因的耐药性突变

高效抗逆转录病毒治疗法（HAART）的推广使用有效地抑制了HIV-1病毒的传播和艾滋病（AIDS）的发病率、死亡率。近年来,HIV-1逆转录酶基因突变所导致的耐药性成为了HAART的治疗失败的主要原因,耐药性突变的检测对于指导病人用药以及新药开发具有重要意义。本工作发展了一种检测HIV-1逆转录酶基因耐药性突变的新方法。采用两步MS-PCR方法检测HIV-1 B亚型野生型和耐药突变型逆转录酶基因突变,检测点包括M41L、K70R、K103N、Y181C和T215,并在两步MS-PCR基础上,设计比野生型引物长的突变型引物,结合微孔板杂交ELISA呈色技术检测各点突变。结果显示,简化的两步MS-PCR能保持灵敏度和特异性高的优点,ELISA的阳性结果与阴性结果的比值（P/N）达到要求,两步MS-PCR结合ELISA方法灵敏度高,操作简单、结果直观、成本低、相对耗时短且能进行高通量检测,其无论在HIV-1耐药性突变及其它的点突变检测中具有较好的临床应用前景。     

土壤噬菌体及其介导的抗生素抗性基因水平转移研究进展

土壤中抗生素耐药性的扩散对全球的公共卫生和食品安全造成威胁,严重挑战人类感染类疾病的预防与治疗.噬菌体介导的抗生素抗性基因(ARGs)的水平转移是环境中抗性基因扩散的重要机制.但是,噬菌体对土壤环境中抗性基因传播的贡献尚未见报道.本文综述了土壤环境中噬菌体的分布特征与影响因子,总结了纯化和富集土壤噬菌体的主要研究方法;...     

土壤中抗性基因的产生,扩散传播以及消减的研究进展

近年来,土壤中残留的大量抗生素不可避免的导致耐药微生物和抗性基因的增加和扩散,引起一系列土壤污染和生态风险。作为一类新兴污染物,抗性基因的污染水平已经远远超出我们的预想,因此对土壤中抗性基因的分布水平、扩散传播及消减技术的研究刻不容缓。本文对国内外土壤中抗生素和抗性基因残留水平进行了总结分析,探讨了土壤中抗性基因的产生、扩散的内在动力和机制。同时,分析了土壤中抗性基因分布和扩散的影响因素,如:抗生素残留水平,土壤理化性质和环境条件等。在此基础上,探讨了土壤抗性基因阻隔和消减技术,包括传统降解方法:高温,光照催化、微波-H2O2-微生物联合处理技术等,并提出新型消解技术:取代活性基团、靶位修饰以及改变外排泵的通透性等。讨论未来在控制抗性基因生态风险,降低其在土壤中的丰度,有效阻截技术的发展趋势。     

抗生素耐药基因在畜禽粪便-土壤系统中的分布、扩散及检测方法

抗生素耐药基因作为一种新型的环境污染物已引起研究者的高度关注。畜禽养殖业长期将抗生素添加到饲料中,在促进动物生长、预防和治疗动物疾病等方面起了重要作用。这些抗生素大多数不能被动物完全吸收,在动物肠道中诱导出耐抗生素细菌和抗生素耐药基因,并随着粪便排出体外。畜禽粪便作为重要的抗生素、耐抗生素细菌和抗生素耐药基因储存库,通过堆粪、施肥等农业活动进入土壤环境中,可刺激土壤中耐抗生素细菌和抗生素耐药基因的富集。耐药基因借助于基因水平转移等方式在土壤介质中进一步传播扩散,甚至进入植物中随食物链传播,对生态环境和人类健康造成极大的威胁。为了正确评估抗生素耐药基因的生态风险,本文结合国内外相关研究,系统阐述了畜禽粪便-土壤系统中抗生素耐药基因的来源、分布及扩散机制,同时探讨了细菌耐药性的主要研究方法,指出堆肥化处理仍是目前去除抗生素耐药基因的主要手段,并对今后的研究方向进行展望。     

Antibiotic resistance in surface water ecosystems: Presence in the aquatic environment,prevention strategies,and risk assessment

Antibiotic-resistant bacteria (ARB) have gained increased notoriety due to their continued detection in environmental media and consequently their threat to human and animal health. The continuing spread of antibiotic resistance throughout the environment is of growing environmental and public health concern, making it difficult to treat harmful resistant diseases. This paper examines the presence of antibiotics, ARB, and antibiotic-resistant genes (ARGs) in aquatic environments; the effectiveness of current water treatment strategies to remove them; and risk assessment methods available that can be used to evaluate the risk from antibiotic resistance. Antibiotics, ARB, and ARGs have been reported at varying levels in wastewater treatment plants, hospital wastewater, irrigation water, recreational water, and drinking water. There are many different water treatments capable of reducing antibiotic resistance (including chlorination, UV, and ozone); however, no one method can fully eliminate it with much variation in the reported effects. Risk assessment models can be used for interpreting field data into the risk to human health from antibiotic resistance. Currently, there is no gold standard risk assessment method for evaluating antibiotic resistance. Methods in this area need further development to reflect evolving risk assessment methodologies and dynamic data as it emerges.     

Aquatic animals promote antibiotic resistance gene dissemination in water via conjugation: Role of different regions within the zebra fish intestinal tract,and impact on fish intestinal microbiota

The aqueous environment is one of many reservoirs of antibiotic resistance genes (ARGs). Fish, as important aquatic animals which possess ideal intestinal niches for bacteria to grow and multiply, may ingest antibiotic resistance bacteria from aqueous environment. The fish gut would be a suitable environment for conjugal gene transfer including those encoding antibiotic resistance. However, little is known in relation to the impact of ingested ARGs or antibiotic resistance bacteria (ARB) on gut microbiota. Here, we applied the cultivation method, qPCR, nuclear molecular genetic marker and 16S rDNA amplicon sequencing technologies to develop a plasmid‐mediated ARG transfer model of zebrafish. Furthermore, we aimed to investigate the dissemination of ARGs in microbial communities of zebrafish guts after donors carrying self‐transferring plasmids that encode ARGs were introduced in aquaria. On average, 15% of faecal bacteria obtained ARGs through RP4‐mediated conjugal transfer. The hindgut was the most important intestinal region supporting ARG dissemination, with concentrations of donor and transconjugant cells almost 25 times higher than those of other intestinal segments. Furthermore, in the hindgut where conjugal transfer occurred most actively, there was remarkable upregulation of the mRNA expression of the RP4 plasmid regulatory genes, trbBp and trfAp. Exogenous bacteria seem to alter bacterial communities by increasing Escherichia and Bacteroides species, while decreasing Aeromonas compared with control groups. We identified the composition of transconjugants and abundance of both cultivable and uncultivable bacteria (the latter accounted for 90.4%–97.2% of total transconjugants). Our study suggests that aquatic animal guts contribute to the spread of ARGs in water environments.     

Status of pathogens,antibiotic resistance genes and antibiotic residues in wastewater treatment systems

Pathogens are becoming nearly untreatable due to the rise in gaining new resistance against standard antibiotics. Coexistence of microbial pathogens, antibiotics and antibiotic resistant genes (ARGs) in wastewater treatment plants (WWTP) provide favourable conditions for the development of new antibiotic resistant bacteria (ARB); facilitate horizontal gene transfer among pathogens and may also serve as a hotspot for the spread of ARB and genes into the environment. In this study, the current status of wastewater treatment systems in the removal of pathogens, ARGs, and antibiotic residues are discussed. WWTP are efficient in removing pathogens and antibiotic residues to a greater extend during secondary and tertiary treatment processes. Recent studies, however, have shown high variations in the presence of pathogens including ARB as well as antibiotic resistance genes (ARG) in the final effluent. Prolonged sludge retention time (SRT) and hydraulic retention time (HRT) during secondary treatment will facilitate antibiotic removal by adsorption and biodegradation. However, the above conditions can also lead to the enhancement of antibiotic resistance process in microbes. Therefore, optimum conditions for the operation of conventional WWTP for the efficient removal of antibiotics are yet to be established. The removal of antibiotic residues can be accelerated by combining conventional activated sludge (CAS) process with an additional treatment technology involving dosing with ozone. The advanced biological treatment method using membrane bioreactors (MBR) in combination with coagulation reportedly has the best ARG removal efficiency, and removes both ARB and extracellular ARGs. While studies have predicted the fate for ARGs in wastewater treatment plants, the mechanisms of ARGs acquisition remains to be conclusively established. Thus, strategies to investigate the underlying mechanism of acquisition of ARGs within the WWTP are also provided in this review.     

食品动物养殖环境中细菌耐药性研究进展

抗生素耐药性被世界卫生组织认为是21世纪人类面临的最大的公共卫生安全问题之一。近年来,抗生素耐药基因作为一种新型污染物而受到广泛关注。养殖场现已成为耐药基因的一个重要储库,耐药菌及耐药基因随着动物排泄物进入环境,从而加速了耐药基因在环境中的传播。畜禽养殖环境中耐药基因和耐药菌可能经食物链、空气等途径传至人类,给人类健康带来巨大威胁。文中结合最新文献,主要介绍了动物养殖场抗菌药物耐药菌和耐药基因的分布特点、耐药基因的持留和传播扩散、研究方法等方面的研究进展,为食品动物养殖环境的抗菌药物耐药性风险评估提供一定支持。     

Research progress on distribution,migration, transformation of antibiotics and antibiotic resistance genes (ARGs) in aquatic environment

Antimicrobial and antibiotics resistance caused by misuse or overuse of antibiotics exposure is a growing and significant threat to global public health. The spread and horizontal transfer of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) by the selective pressure of antibiotics in an aquatic environment is a major public health issue. To develop a better understanding of potential ecological risks die to antibiotics and ARGs, this study mainly summarizes research progress about: (i) the occurrence, concentration, fate, and potential ecological effects of antibiotics and ARGs in various aquatic environments, (ii) the threat, spread, and horizontal gene transfer (HGT) of ARGs, and (iii) the relationship between antibiotics, ARGs, and ARB. Finally, this review also proposes future research direction on antibiotics and ARGs.     

污水处理厂生物气溶胶抗生素抗性污染特征、来源及潜在风险

污水处理厂是抗生素抗性基因（antibiotic resistance genes,ARGs）和抗生素抗性细菌（antibiotic resistant bacteria,ARB）重要的源和汇,生物气溶胶是ARGs和ARB自污水处理厂向周边环境释放的关键载体。目前缺乏对污水处理厂生物气溶胶抗生素抗性污染特征、来源及潜在风险的系统性总结。本文从采样方法、检测方法、逸散特征、来源、潜在危害和风险评估等方面对污水处理厂抗生素抗性污染研究现状进行综述。惯性采样法和过滤法是常用的污水处理厂抗生素抗性生物气溶胶主要采集方法,而宏基因组测序、组装和分箱为其ARGs组成、可移动性和宿主提供了有效的检测方法,抗多药类、抗杆菌肽类、抗氨基糖苷类、抗四环素类、抗β-内酰胺类、抗磺胺类、抗大环内酯类和抗糖肽类等抗性基因在污水处理厂PM₁₀、PM_2.5和PM_1.0颗粒物中广泛检出。格栅间、生化反应池和污泥处理单元是污水处理厂PM₁₀、PM_2.5和PM_1.0负载ARGs和ARB的主要释放单元。污水处理厂不同粒径生物气溶胶中致病性ARB的存在增加了抗生素治疗的难度,而污水和污泥对ARGs和ARB的释放起到了重要的源的贡献。本文在研究内容、研究技术和控制策略等方面也提出了相关展望,以期为污水厂生物气溶胶抗生素抗性污染的监测和防护提供参考和借鉴。