| 초록 |
Temperate phages have been suggested to carry virulence factors and other lysogenic conversion genes that play important roles in pathogenicity. In this study, phage TEM123 in wild-type Staphylococcus aureus from food sources was analyzed with respect to its morphology, genome sequence, and antibiotic resistance conversion ability. Phage TEM123 from a mitomycin C-induced lysate of S. aureus was isolated from foods. Morphological analysis under a transmission electron microscope revealed that it belonged to the family Siphoviridae. The genome of phage TEM123 consisted of a double-stranded DNA of 43,786 bp with a G+C content of 34.06%. A bioinformatics analysis of the phage genome identified 43 putative open reading frames (ORFs). ORF1 encoded a protein that was nearly identical to the metallo- beta;-lactamase enzymes that degrade beta;-lactam antibiotics. After transduction to S. aureus with phage TEM123, the metallo- beta;-lactamase gene was confirmed in the transductant by PCR and sequencing analyses. In a beta;-lactam antibiotic susceptibility test, the transductant was more highly resistant to beta;-lactam antibiotics than S. aureus S133. Phage TEM123 might play a role in the transfer of beta;-lactam antibiotic resistance determinants in S. aureus. Therefore, we suggest that the prophage of S. aureus with its exotoxin is a risk factor for food safety in the food chain through lateral gene transfer. |
