磺胺甲(口恶)唑污染土壤中微生物群落结构与抗生素抗性基因的分布特征

采用盆栽实验模拟磺胺甲■唑污染,通过Illumina高通量测序研究了土壤微生物群落组成的变化,应用普通PCR和微滴数字PCR技术分析了6种抗生素抗性基因的64个抗性基因亚型的分布特征.结果表明,土壤受不同浓度磺胺甲■唑污染120 d后,土壤真菌的多样性无明显变化(P0.05),但土壤细菌的多样性显著降低了(P0.05),土壤细菌和真菌群落结构均发生显著改变,且不同浓度磺胺甲■唑处理土壤的优势细菌与真菌在属水平上存在明显差异.磺胺甲■唑污染使土壤中抗生素抗性基因的多样性增加,且能显著提高磺胺抗性基因sul1的丰度(P0.05),但对磺胺抗性基因sul2、喹诺酮抗性基因floR与cmlA 1、四环素抗性基因tet(34)、tetG 2、tetG 1、tetM与tetA/P的丰度均无显著性影响(P0.05).

Microbial Community Structure and the Distribution of Antibiotic Resistance Genes in Soil Contaminated by Sulfamethoxazole

A pot experiment was carried out to simulate soil contaminated by sulfamethoxazole at different concentrations. The community structure of soil microorganisms was investigated using Illumina high-throughput sequencing, and 64 subtypes of antibiotic resistance genes (ARGs) resistant to six classes of antibiotic were also analyzed by PCR and droplet digital PCR. The results showed that soil contamination with sulfamethoxazole had no significant effect on fungal diversity after 120 days (P>0.05) whereas bacterial diversity was significantly reduced (P<0.05). The microbial community structure of the contaminated soil changed significantly, with the dominant bacterial and fungal genera being significantly different from the control soil. Sulfamethoxazole contamination resulted in an increase in ARG diversity, and the abundance of the sulfonamide resistance gene sul1 increased significantly (P<0.05). However, the abundance of the sulfonamide resistance gene sul2, the quinolone resistance genes floR and cmlA1, and the tetracycline resistance genes tet(34), tetG2, tetG1,tetM, and tetA/P did not show significant changes in the contaminated soil (P>0.05).