天津市中心城区集中供应管网末梢水的抗生素耐药基因污染特征研究

Profile of Antibiotic Resistance Genes in the Terminal Tap Water from the Center Area of Tianjin

为了研究天津市中心城区集中供应管网末梢水的抗生素耐药基因(antibiotic resistance genes,ARGs)污染特征,采集了天津市中心城区6个采样点的管网末梢水样,分别采用微孔滤膜正压过滤法及核酸吸附-洗脱法富集水中细菌和胞外核酸后,利用实时定量PCR技术对15种胞内ARGs和胞外ARGs进行定量检测。结果表明,在待检的15种ARGs中,除了耐碳青霉烯类bla KPC未被发现外,其余ARGs(mcr-1、van A、bla NDM-1、aad A、bla TEM、sul1、tet M、tet A、dfr A1、rpo B1、cat A1、erm B、kat G和qnr A)均在天津市中心城区所有管网末梢水样中检出,其中,mcr-1、van A、aad A、bla TEM、sul1、tet M、tet A和dfr A1等8种在细胞内外含量均较高,分别占待检的胞内ARGs和胞外ARGs总量的97.25%和99.18%,以aad A最高,其次为bla TEM和sul1;细胞内ARGs总绝对浓度高于细胞外(P<0.05),前者为后者的3.8倍。天津市中心城区集中供应管网末梢普遍存在胞内ARGs和胞外ARGs污染,且细胞内外超级耐药基因均有检出。

To study the profile of intracellular and extracellular antibiotic resistant genes(iARGs and eARGs)in the terminal tap water from the six central districts of Tianjin City,tap water samples were collected from each area.After bacteria and free eDNA were collected with filter membrane or adsorption-elution technique,quantitative real-time PCR technology was used to detect 15 types of iARGs and eARGs.We discovered that all the observed ARGs with the exception of bla KPC were found in the terminal tap water.Above all,the contents of mcr-1,van A,bla NDM-1,aad A,bla TEM,sul1,tet M,tet A and dfr A1 occupied the most,reaching to 97.25%and 99.18%of the total of iARGs and eARGs.Gene aad A was the highest and bla TEM,sul1 came to the next.The absolute abundance of iARGs was 3.8 times higher than that of eARGs.The pollution of iARGs and eARGs occurred in the terminal tap water in Tianjin,especially the super antibiotic resistance genes.