Antibiotics and Antibiotic Resistance Genes in Sediment of Honghu Lake and East Dongting Lake, China

Abstract

Sediment is an ideal medium for the aggregation and dissemination of antibiotics and antibiotic resistance genes (ARGs). The levels of antibiotics and ARGs in Honghu Lake and East Dongting Lake of central China were investigated in this study. The concentrations of eight antibiotics (four sulfonamides and four tetracyclines) in Honghu Lake were in the range 90.00-437.43 μg kg (dry weight (dw)) with mean value of 278.21 μg kg dw, which was significantly higher than those in East Dongting Lake (60.02-321.04 μg kg dw, mean value of 195.70 μg kg dw). Among the tested three sulfonamide resistance genes (sul) and eight tetracycline resistance genes (tet), sul1, sul2, tetA, tetC, and tetM had 100 % detection frequency in sediment samples of East Dongting Lake, while only sul1, sul2, and tetC were observed in all samples of Honghu Lake. The relative abundance of sul2 was higher than that of sul1 at p < 0.05 level in both lakes. The relative abundance of tet genes in East Dongting Lake was in the following order: tetM > tetB > tetC > tetA. The relative abundance of sul1, sul2, and tetC in East Dongting Lake was significantly higher than those in Honghu Lake. The abundance of background bacteria may play an important role in the horizontal spread of sul2 and tetC genes in Honghu Lake and sul1 in East Dongting Lake, respectively. Redundancy analysis indicated that tetracyclines may play a more important role than sulfonamides in the abundance of sul1, sul2, and tetC gens in Honghu Lake and East Dongting Lake.

Occurrence, Distribution, and Risk Assessment of Antibiotics in a Subtropical River-Reservoir System

“…A similar phenomenon was also found in the Baiyangdian Lake [61]. However, this finding is inconsistent with previous studies in the Yangtze Estuary [39], South Yellow Sea [29], Honghu Lake and East Dongting Lake [62].…”

Distribution patterns of antibiotic residues in an urban river catchment

“…A total of 14 out of 23 target antibiotics were found in sediments at Ningbo city with concentrations ranging from not detected or < LOQ (limit of quantification) to 4496.0 ng/g (Fig. ), magnitudes similar to those commonly found in Chinese freshwater and marine sediments (Liu et al, ; Yang et al, ). The residual patterns of the antibiotics were generally related to medicine prescription and environmental stability.…”

Occurrence and ecological hazard assessment of selected antibiotics in the surface waters in and around Lake Honghu, China

“…Honghu Lake, which is located in central China, suffers from high-intensity human activities and lack of adequate sewage treatment facilities (wastewater treatment rate at only 38%) (Yang et al, 2016). For example, the densities of population, livestock, and poultry in Honghu Lake watershed are approximately 570 individuals, 800 pigs, and 14,000 poultry per square kilometers (JBS, 2016); moreover, over 40% of the total area of Honghu Lake is used as aquafarms for high-density culturing of fish, crabs, crawfish, and shellfish, with annual products of approximately 0.3 million tons Yang et al, 2016).…”

“…These results indicated that the aquaculture application and the point or non-point discharge are mainly responsible for the occurrence of antibiotics in the Honghu Lake region. This phenomenon is mainly caused by the high-intensity and large-area aquaculture in Honghu Lake (fishery enclosure in Honghu Lake was over 40% of the total area of the lake) and lack of the wastewater treatment facilities in this region (Yang et al, 2016).…”