Purpose: To determine the prevalence and genetic basis of tetracycline resistance in Staphylococcus aureus. Methods: One hundred and thirty (130) clinical isolates of S. aureus were collected from Khyber Teaching Hospital, Peshawar, Pakistan. Susceptibility to antibiotics (doxycycline, tetracycline and minocycline) was determined by Kirby-Bauer disc diffusion method with minimum inhibitory concentration (MIC) evaluated on Muller-Hinton agar as described by the Clinical and Laboratory Standards Institute (CLSI). The tetracyclineresistant strains (TET-R) were screened by polymerase chain reaction (PCR) for the presence of four common tetracycline resistance determinants, viz, tet(K), tet(L), tet(M) and tet(O). Results: Sixty (46.0 %) of these isolates were methicillin-resistant S. aureus (MRSA) while 70 (54.0 %) were methicillin-susceptible S. aureus (MSSA). Seventy four (56.9 %) strains were resistant to tetracycline (TET-R), 30 (23.1 %) to minocycline and 23 (17.7 %)

Staphylococcus aureus has vital importance in veterinary medicine. Within the ruminants, it is one of the major causes of mastitis, the problem that was and is, with no definite solution to date. Along with that, it also affects the health of animals, pets, and poultry in several ways as the tissue tropism for this organism in poultry is the bones and the joints. This review is focused on habitat, species differentiation, differential biochemical tests, pathogenesis, clinical infections, economic importance, public health significance, immune response, the regulation of virulence in the staphylococci, and cytokines response against S. aureus.