**1. Introduction**

Staphylococci are Gram-positive cocci bacteria of 1 pico-meter diameter. They are observed with gram staining under the microscope as a bunch of grapes. The word staphylococcus is originated from the Greek words staphyle and kokkos. Staphyle means the "bunch of grapes", while the word kokkos means "the berry". The normal habitat of staphylococci is skin and mucus membranes. There are approximately 30 species of staphylococcus. They act as commensals but some of them are opportunistic pathogens too. They a famous for their pyogenic infectioncausing property. Most staphylococci are facultative anaerobes, non-motile, oxidase-negative, non-spore-forming, and catalase-positive. S. aureus subsp. aureus is the coagulase-positive that has very much importance concerning the disease status of animals. Production of coagulase is directly correlated with the pathogenicity of the staphylococcus i.e. coagulase-negative bacteria are usually non0-pathogenic to animals and humans [1]. They can be grown on non-enriched media. They are facultative anaerobes and non-motile. They are found as commensals on mucous membranes and skin. They are stable in the environment **Figure 1** [99].

**Figure 1.** *'Bunches of grapes' appearance of Staphylococci. Modified from [1].*
