Department of Microbiology and Biomonitoring, Faculty of Agriculture and Economics, University of Agriculture in Kraków, Adam Mickiewicz Ave. 24/28, 30-059 Kraków, Poland.
Department of Forest Ecosystems Protection, Faculty of Forestry, University of Agriculture in Kraków, 29 Listopada Ave. 46, 31-425 Kraków, Poland.
Sci Total Environ. 2022 Feb 1;806(Pt 3):151355. doi: 10.1016/j.scitotenv.2021.151355. Epub 2021 Nov 2.
Mountain areas in Poland are among the most frequented tourist destinations and such intensive tourism negatively affects the natural environment. The COVID-19 pandemic and the resulting lockdown restricted travel for a few months in 2020, providing a unique opportunity to observe the studied mountain environment without the impact of typical tourist traffic. This study is based on the determination of antibiotic content, hydrochemical parameters, enumeration of culturable bacterial water quality indicators, antimicrobial susceptibility tests together with extended spectrum beta-lactamase (ESBL) gene detection in waterborne E. coli and NGS-based bacterial community composition at six sites along the Białka river valley (one of the most popular touristic regions in Poland) in three periods: in summer and winter tourist seasons and during the COVID-19 lockdown. The results of individual measurements showed decreased numbers of bacterial indicators of water contamination (e.g. numbers of E. coli dropped from 99 × 10 CFU/100 ml to 12 CFU/100 ml at the most contaminated site) and the share of antimicrobial resistant E. coli (total resistance dropped from 21% in summer to 9% during lockdown, share of multidrug resistant strains from 100 to 44%, and ESBL from 20% in summer to none during lockdown). Antibiotic concentrations were the highest during lockdown. The use of multivariate analysis (principal component analysis - PCA and heatmaps) revealed a clear pattern of tourism-related anthropogenic pressure on the water environment and positive impact of COVID-19 lockdown on water quality. PCA distinguished three major factors determining water quality: F1 shows strong effect of anthropogenic pressure; F2 describes the lockdown-related quality restoration processes; F3 is semi-natural and describes the differences between the most pristine and most anthropogenically-impacted waters.
波兰山区是最受欢迎的旅游目的地之一，这种密集的旅游业对自然环境产生了负面影响。2020 年，由于 COVID-19 大流行和随之而来的封锁，旅行被限制了几个月，这为在没有典型旅游交通影响的情况下观察研究中的山区环境提供了一个独特的机会。本研究基于在白雷克河谷（波兰最受欢迎的旅游区之一）的六个地点，在三个时期（夏季和冬季旅游季节以及 COVID-19 封锁期间），沿白雷克河谷（波兰最受欢迎的旅游区之一）的六个地点，对水样中抗生素含量、水化学参数、可培养细菌水质指标计数、抗菌药敏试验以及水中大肠杆菌的扩展谱β-内酰胺酶（ESBL）基因检测以及基于 NGS 的细菌群落组成进行了研究。在最污染的地点，水样中污染细菌指标的数量（例如大肠杆菌数量从 99×10 CFU/100ml 下降到 12 CFU/100ml）和抗菌药物耐药大肠杆菌的比例（总耐药率从夏季的 21%下降到封锁期间的 9%，多药耐药株的比例从 100%下降到 44%，ESBL 从夏季的 20%下降到封锁期间的 0%）均有所下降。抗生素浓度在封锁期间最高。多元分析（主成分分析-PCA 和热图）的使用揭示了旅游业相关人为压力对水环境的明显影响，以及 COVID-19 封锁对水质的积极影响。PCA 区分了决定水质的三个主要因素：F1 显示出人为压力的强烈影响；F2 描述了与封锁相关的质量恢复过程；F3 是半自然的，描述了最原始和受人为影响最大的水域之间的差异。
