Marine bacteria harbor the sulfonamide resistance gene sul4 without mobile genetic elements

Marine bacteria are possible reservoirs of antibiotic-resistance genes (ARGs) originating not only from clinical and terrestrial hot spots but also the marine environment. We report here for first time a higher rate sulfonamide-resistance gene sul4 in bacterial isolates compared with other sul genes. Among four ( sul1 , sul2 sul3 ), was most abundant (45%) 74 sulfonamide-resistant by PCR screening. The order abundance (33 isolates) >sul2 (6 >sul3 (5 >sul1 (1 isolate). Whole-genome sequencing 23 -expressing α- γ-proteobacteria bacilli revealed that accompanied known mobile genetic elements. This suggests these is clonally transferred horizontally transferable. Folate metabolism formed cluster suggesting area plays role folate metabolism, at which functions as dihydropteroate synthase. Thus, might be expressed species function synthesis, it transferable ARG.