Genomic characteristics of cfr and fexA carrying Staphylococcus aureus isolated from pig carcasses in Korea

This study evaluated the genetic characteristics of linezolid-resistantStaphylococcus aureus strains isolated from pig carcasses and further clarified potential resistance and virulence mechanisms in a newly identified sequence type. Of more than 2500 strains isolated in a prior study, 15 isolated from pig carcasses exhibited linezolid resistance (minimum inhibitory concentration  ≥ 8 mg/L). The strains were characterized in detail by genomic analysis. Linezolid-resistantS. aureus strains exhibited a high degree of genetic lineage diversity, with one strain (LNZ_R_SAU_64) belonging to ST8004, which has not been reported previously. The 15 strains carried a total of 21 antibiotic resistance genes, and five carriedmecA associated with methicillin resistance. All strains harboredcfr andfexA, which mediate resistance to linezolid, phenicol, and other antibiotics. Moreover, the strains carried enterotoxin gene clusters, including the hemolysin, leukotoxin, and protease genes, which are associated with humans or livestock. Some genes were predicted to be carried in plasmids or flanked byISSau9 and the transposonTn554, thus being transmittable between staphylococci. Strains carrying the plasmid repliconrepUS5 displayed high sequence similarity (99%) to the previously reported strain pSA737 in human clinical samples in the United States. The results illustrate the need for continuous monitoring of the prevalence and transmission of linezolid-resistantS. aureus isolated from an...
Source: Veterinary Research - Category: Veterinary Research Source Type: research