[Distribution of Microplastic and Antibiotic Resistance Gene Pollution in Jiulong River Estuary]

Pollution from microplastics (MPs) and antibiotic resistance genes (ARGs) is prevalent in estuarine regions. MPs may also enrich ARGs and increase the spread of ARGs. This study investigated the distribution characteristics of MPs in surface water and sediments from different stations in Jiulong River estuary for the first time, determined eight common ARGs abundance in each sample, and analyzed the correlation between MPs content and ARGs abundance. The results showed:① MPs concentrations in the Jiulong River estuary water environment ranged from 2 to 66 n·L^-1, and the sediment content range (dw) was 8 to 85 n·kg^-1. The main materials of MPs detected were polypropylene (PP), polystyrene (PS), and polyethylene (PE). More than 85% of the MPs were smaller than 1 mm. ② The predominant ARGs in the estuary were tetracycline resistance genes tetC and tetG and sulfonamide resistance gene sul2; the relative abundance of ARGs in the surface water showed a significant negative correlation with salinity. ③ A positive correlation existed among MPs concentration, ARGs relative abundance, and class1 integron geneintI1, which implied that MPs may promote the spread of ARGs in seawater.