Onalenna Onthatile, Rahube Teddie O
Department of Biological Sciences & Biotechnology, Faculty of Science, Botswana International University of Science & Technology, Palapye, Botswana.
Heliyon. 2022 Mar 11;8(3):e09089. doi: 10.1016/j.heliyon.2022.e09089. eCollection 2022 Mar.
Water scarcity is one of the main challenges in sustainable agricultural development particularly in developing countries therefore, irrigation of food crops with wastewater effluent has become a common practice in order to meet the growing food demand. The aim of this study was to determine the impact of wastewater irrigation on bacterial community and antibiotic resistance dynamics in soil and vegetables in an agricultural setting. To determine bacterial diversity, occurrence and overall dynamics of antibiotic resistant genes (ARGs) in effluent irrigated soil and vegetables, 16S rRNA gene metagenomics, shotgun metagenomics and molecular PCR technique were utilized. A shift in bacterial community profile was observed as notable reduction in proteobacteria and increase in firmicutes phyla from the microcosm soil following wastewater effluent irrigation. Shotgun metagenomics revealed diverse ARGs belonging to at least nine different classes of antibiotics in the effluent wastewater. However, only (beta-lactamase) and A (aminoglycoside) resistance gene sequences were identified in microcosm soil following irrigation and only was detected on effluent irrigated vegetable surfaces (spinach and beetroots). From the study, only gene was identified across all samples; effluent wastewater, effluent-treated soil, and vegetables. The data suggests a possible dissemination and persistence of the beta-lactamase gene from effluent wastewater into agricultural soil and vegetables. This study enhances our understanding of antibiotic resistance spread and highlights the importance of monitoring antibiotic resistance in agro-systems, which is critical for informing policies aimed at sustainable use of wastewater effluent in water-stressed countries.
水资源短缺是可持续农业发展面临的主要挑战之一，特别是在发展中国家。因此，为满足不断增长的粮食需求，利用废水灌溉粮食作物已成为一种常见做法。本研究的目的是确定农业环境中废水灌溉对土壤和蔬菜中细菌群落及抗生素抗性动态的影响。为了确定废水灌溉土壤和蔬菜中抗生素抗性基因（ARGs）的细菌多样性、存在情况及总体动态，采用了16S rRNA基因宏基因组学、鸟枪法宏基因组学和分子PCR技术。废水灌溉后，在微观土壤中观察到细菌群落谱的变化，变形菌显著减少，厚壁菌门增加。鸟枪法宏基因组学揭示了废水中至少属于九种不同抗生素类别的多种ARGs。然而，灌溉后在微观土壤中仅鉴定出bla（β-内酰胺酶）和aac（氨基糖苷）抗性基因序列，在废水灌溉的蔬菜表面（菠菜和甜菜根）仅检测到bla。在该研究中，在所有样品（废水、废水处理过的土壤和蔬菜）中仅鉴定出bla基因。数据表明β-内酰胺酶bla基因可能从废水传播并持续存在于农业土壤和蔬菜中。本研究增进了我们对抗生素抗性传播的理解，并突出了监测农业系统中抗生素抗性的重要性，这对于为缺水国家制定旨在可持续利用废水的政策至关重要。
