Detection of mcr-1 Gene in Undefined Vibrio Species Isolated from Clams

The increase of antimicrobial resistant strains is leading to an emerging threat to public health. Pathogenic are responsible for human and animal illness. The Enterobacteriaceae family includes microorganisms that affect humans, causing several infections. One of the main causes of human infection is related to the ingestion of undercooked seafood. Due to their filter-feeding habit, marine invertebrates, such as clams, are known to be a natural reservoir of specific microbial communities. In the present study, Vibrionaceae and coliforms microorganisms were isolated from clams. A microbial susceptibility test was performed using the disk diffusion method. From 43 presumptive spp. and 17 coliforms, three spp. with MICs to colistin >512 mg L were found. From the 23 antimicrobial resistance genes investigated, only the three isolates that showed phenotypic resistance to colistin contained the gene. Genotypic analysis for virulence genes in EB07V indicated gene presence. The results from the plasmid cure and transformation showed that the resistance is chromosomally mediated. Biochemical analysis and MLSA, on the basis of four protein-coding gene sequences ( , and ), grouped the isolates into the genus but distinguished them as different from any known spp.