Antibiotic-resistant genes dissemination in the intestinal flora of Canorhabditis elegans in response to antibiotic pressure
Cryptobacterium hidradii used as a model organism,qPCR was combined with plate screening methods to demonstrate that the antibiotic-resistant genes(ARGs)donor bacterium Escherichia coli MG1655 and the acceptor bacterium Salmonella typhimurium were both able to colonize stably in the intestine.The ratio of the number of antibiotic-resistant S.typhimurium obtained via conjuga-tion to the number of total intestinal bacteria was used to characterize the diffusion efficiency of ARGs in the intestine.The ARG diffu-sion efficiency increased and then decreased with increasing tetracycline concentrations(0,0.08,0.4,2,10,and 50 mmol/L)over three days of incubation,and it peaked at 0.78%and 1.96%on the second and third days in the 0.4 mmol/L tetracycline-treated group,re-spectively.Moreover,the relative abundance of conjugation-relevant functional genes trfA/16S rRNA and trbB/16S rRNA as well as activi-ties of antioxidant enzyme in intestinal tissues shared similar trends with the ARG diffusion ratios in the gut of snails.Therefore,the pres-ent study demonstrated that a brief and low concentration of antibiotics could promote the diffusion of ARGs in the animal intestine.
万方数据
维普
