Quillaguamán Jorge, Guzmán Daniel, Campero Melina, Hoepfner Claudia, Relos Laura, Mendieta Daniela, Higdon Shawn M, Eid Daniel, Fernández Carla E
Center of Biotechnology, Faculty of Science and Technology, Universidad Mayor de San Simón, Cochabamba, Bolivia.
Center of Biotechnology, Faculty of Science and Technology, Universidad Mayor de San Simón, Cochabamba, Bolivia.
Environ Pollut. 2021 Jan 11;273:116488. doi: 10.1016/j.envpol.2021.116488.
Bacterial resistance to antibiotics is one of the greatest threats to the modern human population. Paradoxically, urban settlements are often culpable in generating such resistance by influencing the adaptation of bacterial communities via pollution of natural ecosystems. Urban lakes are well-known examples of this problem, as they often receive discharges of both domestic and industrial wastewater. In this study, we used shotgun metagenome sequencing to examine the microbial diversity of water and sediment samples of Lake Alalay, a polluted urban lake near Cochabamba, Bolivia. We found that Proteobacteria dominated the relative abundance of both water and sediment samples at levels over 25% and that a significant proportion of the microbial diversity could not be classified (about 9% in water and 22% in sediment). Further metagenomic investigation of antimicrobial resistance (AR) genes identified 277 and 150 AR genes in water and sediment samples, respectively. These included genes with functional annotations for resistance to fluoroquinolones, tetracyclines, phenicols, macrolides, beta-lactams, and rifamycin. A high number of genes involved in bacterial virulence also occurred in both water and sediment samples (169 and 283, respectively), where the virulence gene pscP normally found in the Pseudomonas aeruginosa type III secretion system had the highest relative abundance. Isolated and identified bacteria from water samples also revealed the presence of pathogenic bacteria among the microbiota of Lake Alalay. Seeing as most AR and virulence genes detected in this study are commonly described in nosocomial infections, we provide evidence suggesting that the microbial ecosystem of Lake Alalay presents a severe health risk to the surrounding population.
细菌对抗生素的耐药性是现代人类面临的最大威胁之一。矛盾的是，城市住区往往难辞其咎，因为它们通过污染自然生态系统影响细菌群落的适应性，从而产生这种耐药性。城市湖泊就是这一问题的典型例子，因为它们常常接纳生活污水和工业废水排放。在本研究中，我们使用鸟枪法宏基因组测序来检测阿拉莱湖（位于玻利维亚科恰班巴附近的一个受污染城市湖泊）水和沉积物样本中的微生物多样性。我们发现，变形菌门在水和沉积物样本的相对丰度中占主导地位，超过25%，并且很大一部分微生物多样性无法分类（水中约为9%，沉积物中约为22%）。对抗菌素耐药性（AR）基因的进一步宏基因组研究在水和沉积物样本中分别鉴定出277个和150个AR基因。这些基因包括对氟喹诺酮类、四环素类、酚类、大环内酯类、β-内酰胺类和利福霉素具有耐药性功能注释的基因。水和沉积物样本中还出现了大量与细菌毒力相关的基因（分别为169个和283个），其中通常在铜绿假单胞菌III型分泌系统中发现的毒力基因pscP相对丰度最高。从水样中分离和鉴定出的细菌也揭示了阿拉莱湖微生物群中存在病原菌。鉴于本研究中检测到的大多数AR和毒力基因通常在医院感染中出现，我们提供的证据表明，阿拉莱湖的微生物生态系统对周围人群构成了严重的健康风险。
