洪湖养殖区水环境中微生物的耐药性及其群落功能多样性研究

为探讨抗生素对水产养殖环境微生物的影响,本研究通过采集洪湖养殖区地下水、湖水和鱼塘水,分别分析其细菌、真菌、放线菌数量及相应耐药(磺胺甲恶唑)微生物的分布规律,探讨耐药微生物数量及耐药微生物占比与磺胺抗生素浓度之间的相关性,并采用Biolog法研究不同水体中微生物群落功能多样性差异。结果表明,不同水体中微生物数量分布规律为:鱼塘水湖水地下水,而湖水和鱼塘水中的微生物数量受人为活动影响差异较大。三类水体均有不同程度耐药微生物检出,耐药微生物数量分布规律为:鱼塘水湖水地下水;耐药微生物占比分布规律为:湖水鱼塘水地下水。地下水中耐药微生物数量与磺胺抗生素浓度无显著相关性,而地表水中耐药细菌、耐药真菌数量及与磺胺吡啶和磺胺二甲基嘧啶浓度呈显著正相关;地表水中耐药细菌与耐药放线菌占比均与磺胺砒啶呈显著相关。Biolog多样性分析结果表明,地表水微生物群落代谢活性和碳源利用性均高于地下水,说明洪湖湖水和鱼塘水利用不同碳源的微生物物种较丰富。研究表明,不同环境水体中微生物的数量和耐药性以及群落功能多样性均有差异,该差异与人类活动和抗生素浓度有一定相关性。

The antibiotic resistance of microorganisms and the functional diversity of microbial communities in the aquaculture environments of Honghu Lake, China

For a better understanding of the influence of antibiotics on microbes in aquaculture environments, samples were collected from groundwater, lake water, and fish ponds in the aquaculture areas of Honghu Lake. The number of bacteria, fungi, and actinomycetes, and their antibiotic resistances to sulfonamides in different water samples were studied. The correlations of the number of antibiotic resistant microorganisms, and the proportions of resistant population with the concentration of sulfonamides were analyzed. The functional diversity of the microbial communities was studied by Biolog analysis. The results showed that the number of microorganisms in different water samples were as follows:fish ponds > lake water > ground water; The microbial numbers in lake water and fish ponds had larger differences due to the influence of human activities. Meanwhile, the proportions of resistant microorganisms were in the order:lake water > fish ponds > ground water. A significant positive correlation was observed between the number of resistant bacteria and fungi, and the concentration of pyridine sulfonamide and sulfamethazine in surface water, although no such significant correlations were found in the case of groundwater. Furthermore,the proportions of resistant bacteria and actinomycetes in surface water were significantly correlated with the concentrations of pyridine sulfonamide. The results of Biolog analyses showed that the metabolic activity and the carbon source utilization of microbial communities in surface water were higher than that of ground water, which indicated the rich microbial species for the different carbon source utilizations in lake water and fish ponds. In summary, the number of microorganisms, their antibiotic resistances, and the functional diversity of the microbial community in various water environments were different, and the differences were related to human activities and antibiotic concentrations.