Low Concentrations of Antibiotics Alter Microbial Communities and Induce High Abundances of Antibiotic-Resistant Genes in Ornamental Water

Antibiotic resistance poses a significant threat to the public health domain. A favorable platform for generating and disseminating antibiotic-resistant genes (ARGs) and antibiotic-resistant bacteria (ARB) is provided by landscaped fish ponds created by urbanization. This research delved into the effects exerted by different concentrations of specific antibiotics, namely tetracycline and ciprofloxacin, on the microbial community composition present in water samples obtained from a landscape pond. Additionally, we analyzed the abundance of ARGs and the class 1 integron-integrase gene (intI1), and identified potential hosts of ARGs. The results indicated that the consistent administration of antibiotics significantly influenced the microbial community structure, resulting in variations within both bacterial communities and functionalities. Furthermore, the absolute quantities of ARGs, including tetA, tetC, qnrA, and qnrS, as well as the integrase gene intI1, exhibited augmentation in response to varying types and concentrations of antibiotics. Notably, the regular input of low concentrations of antibiotics produced higher levels of abundance of ARGs than the regular input of higher concentrations of antibiotics. The use of different types of antibiotics led to diverse host bacteria structures.

Automated summary

Antibiotic resistance is a major threat to public health, and landscaped fish ponds created by urbanization provide a favorable environment for the generation and spread of antibiotic-resistant genes and bacteria. This study investigated the effects of specific antibiotics (tetracycline and ciprofloxacin) on the microbial community in water samples from a landscape pond. The results showed that the administration of antibiotics influenced the microbial community structure and increased the abundance of antibiotic-resistant genes.