摘要
城市污泥中含有大量肠球菌,可携带抗生素抗性基因(antibiotic resistance genes,ARGs)和毒力基因(virulence gene,VGs),从而具有潜在的耐药性和致病性,对人类健康存在巨大威胁.为此考察了热水解污泥在中温(40℃)/高温(55℃)厌氧消化过程中肠球菌的耐药表型、基因型及携带VGs的变化规律.结果表明,厌氧进泥中肠球菌对阿奇霉素的耐药率均显著高于螺旋霉素和四环素.高温厌氧对肠球菌的数量及耐药性具有更好地控制及削减效果.高温厌氧消化可能会促进四环素类抗性基因在肠球菌的表达.中温、高温厌氧消化可促进ARGs在肠球菌中发生水平转移,导致其潜在双重甚至多重耐药性增加.中温厌氧消化可降低肠球菌同时具有潜在致病性和耐药性的几率,而高温厌氧消化则会增加此风险.
Municipal sludge contains large amounts of enterococci,which can harbor antibiotic resistance genes( ARGs) and virulence genes( VGs). ARG-and VG-containing enterococci therefore present potential resistance and virulence and,as a consequence,represent a significant health risk to humans. Therefore,the resistance phenotype of enterococci and the prevalence of ARGs and VGs in the enterococci isolated from the mesophilic( 40℃) and thermophilic( 55℃) anaerobic digestion of thermal hydrolyzed sludge was investigated. Results showed that the enterococci isolated from thermal hydrolyzed sludge showed significantly higher resistance to azithromycin than that to spiramycin and tetracycline. Thermophilic anaerobic digestion resulted in a greater reduction of enterococci abundance( by two orders of magnitude and one order of magnitude,respectively),and a greater reduction in the antibiotic resistance rates of the enterococci. However,thermophilic digestion can promote the expression of tetracycline resistance genes in the enterococci.Furthermore,both mesophilic and thermophilic digestion can facilitate horizontal genes transfer( HGT) between enterococci,which might result in an increase in the occurrence of double-or multiple-resistance. Mesophilic digestion reduced the prevalence of cooccurring ARGs and VGs in enterococci,while thermophilic digestion had the opposite effect. This research improves understanding of the occurrence and fate of ARGs and VGs in potential pathogens during the treatment of municipal sludge.
作者
李慧莉
裴媛玫
李姗
何芙蓉
杨月婷
魏源送
佟娟
LI Hui-li;PEI Yuan-mei;LI Shan;HE Fu-rong;YANG Yue-ting;WEI Yuan-song;TONG Juan(School of Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Research Center for EcoEnvironmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;School of Environmental and Chemical Engineering,Xi’an Polytechnic University,Xi’an 710048,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2019年第7期3270-3275,共6页
Environmental Science
基金
国家自然科学基金项目(51578535,51568039)
