Molecular Comparison Between Resistance Genes in Staphylococcus aureus Clinically Isolated from Cattle and Camels in Southern Egypt

Abstract

S. aureus is one of the most common organisms associated with infections among dairy animals with frequent and rapid development of antibiotic resistance. The presence of genes encoding aminoglycoside resistance tetracycline resistance, and beta-lactam resistance were detected by whole genome sequencing. Seventy-nine S. aureus clinical isolates were isolated from milk samples of dairy cattle and she-camels in Southern Egypt. The sequences of resistant genes extracted from the whole genome sequences of the bacterial chromosome that was done through shotgun sequencing, through phylogenetic analysis, all resistant genes sequences were arranged into two main clusters. The first clusters co0ntain mecA genes, aminoglycosides, fusB gene as well as blaz gene except All, and two reference genes (AJ302698 and AP003139). The second cluster contains mainly the tet(k) and tet(38) genes which are more similar to each other, in addition to mecA reference gene (AB512767) and two blaz reference genes (AJ302698 & AP003139). The phylogenic tree revealed that all resistant genes are more or less stable genes such as mecA, aminoglycosides, tet(k), tet(38), and fusB except blaz gene showing more variations. Molecular detection continues to be increased to establish antimicrobial resistance trends for S. aureus found in subclinical mastitis of dairy animals.