北江河水中抗生素抗性基因污染初步研究（Preliminary Studies on the Pollution Levels of Antibiotic Resistance Genes in the Water of Beijiang River, South China）

环境中细菌的耐药性,尤其是对抗生素的耐药性已成为影响生态环境的重要因素.论文采用抗生素抗性平板法调查了北江河水中四环素、红霉素及磺胺类这3类抗生素耐药性细菌的存在,采用定性PCR及荧光定量PCR方法分别研究了该水域sul1和sul2这2种磺胺类抗生素抗性基因(ARGs)的存在和含量水平.结果表明,所采集北江水域的9个样品中有5个对四环素有耐药性,7个对红霉素有耐药性,8个对磺胺二甲嘧啶有耐药性;定性PCR实验并经基因测序结果证实,5个样品含有sul1,4个样品含有sul2.进一步的PCR定量分析结果显示,7个样品中均检出sul1和sul2磺胺抗性基因,它们与内对照基因16S-rRNA表达量比值分别在10-2.56~10-0.52及10-3.25~10-1.24范围内,该结果显著高于美国科罗拉多州北部河流的研究结果.此外,数据分析也发现,sul1和sul2磺胺抗性基因的含量水平与该区域水中磺胺含量分布具有一定的相关性,表明外源性抗生素对河流的污染是诱导抗性基因的重要因素.

Preliminary Studies on the Pollution Levels of Antibiotic Resistance Genes in the Water of Beijiang River, South China

The bacterial resistance and antibiotic resistance genes (ARGs) among 9 water samples along Beijiang River,South China,were investigated in this work.Culture-based approach was used for the resistance level checks of three classes of antibiotics including tetracycline (TET),macrolides (ERY)and sulfonamides(SMT).Polymerase chain reaction (PCR) assay were applied to detect the presence/absence of two sulfonamide ARGs(sul1 and sul2).It Was found that 8 samples were resistant to TET,5 to ERY and 7 to SMT,respectively.Five samples with sul1 and four samples with sul2 were found in the samples using PCR assay and gene sequence confmnation.Moreover,it was obtained that the ratios of copy values of sul1 or sul2 to 16S-rRNA,reflecting the ARG pollution level,ranged from 10~(-2.56) to 10~(-0.52) and 10~(-3.25) to 10~(-1.24).respectively.in the seven water samples.The levels of ARGs were much higher than those obtained in the water samples from Northern Colorado River.Also.it was found that the ratios of ARGs had good correlation to the concentrations of the selected SMTs occurred in water samples in Beijiang River.