Comparative analysis of common and unique targets in drug resistant strains of staphylococcus aureus

Abstract

The increasing number of drug-resistant strains of Staphylococcus aureus necessitated the identification of potential drug targets specific to the strain of interest. The chromosomal and plasmid genes of S. aureus strains N315, JH1, and JH9 were compared with Mu50 strain to find common (core) and unique (strain-specific) genes in the present study. In silico analysis of genomics data of S. aureus strains N315, JH1, and JH9 with vancomycinresistant strain Mu50 showed total number of unique genes higher in Mu50 and least in N315. The presence of higher number of unique genes in Mu50 signifies their role in drug resistance mechanism. In S. aureus strain Mu50, the chromosomal genes showed tetracycline resistance protein and ABC transporters. Whereas, plasmid genes showed transposase, N-acetyltransferase, and truncated resolvase. In S. aureus strain N315, chromosomal genes showed more number of hypothetical proteins. Whereas, plasmid genes showed arsenical resistance proteins, arsenic efflux pump protein, CadD, CadX, blaR1, and penicillinase repressor. In S. aureus strains JH1 and JH9, chromosomal genes showed mainly phage regulatory proteins, and plasmid genes showed arsenic and cadmium resistance regulatory proteins. Furthermore, human proteome and gut flora non-pathogenic proteomes were compared with proteome of these strains to find target proteins specific to the strain of interest and not present in host. In conclusion, identification of unique genes in these strains provided insights on differences in drug resistance potential.