Cultivation of Staphylococci
Staphylococcus is a genus of round, grape-like cluster forming gram-positive bacteria. They are facultative anaerobes and grow in the presence of bile salts. Most species are harmless and reside normally on the skin and mucous membranes of humans and animals. Found worldwide, they are a small component of the natural soil microbial flora. One of the most important phenotypical features used to classify staphylococci is their ability to produce coagulase, an enzyme that causes the formation of blood clots. Several species are currently recognized as being coagulase-positive, including S. aureus, S. delphini, S. hyicus, S. intermedius, S. lutrae, S. pseudintermedius and S. schleiferi subsp. coagulans.
Merck provides high quality, consistent dehydrated culture media for the enrichment, isolation and enumeration of staphylococci in the form of granules. Like all Merck culture media, they are quality controlled according to stringent standards, guaranteeing the consistent high quality of our products. Merck’s uniquely granulated culture media are not only convenient but also safe, meeting the highest industry performance standards as described in ISO 11133. Granulation significantly reduces dust and thus inhalation of hazardous media components that cause allergic responses. In addition, it minimizes contamination of the work environment.
Staphylococcus can cause a wide variety of diseases in humans and other animals through either toxin production or tissue penetration. Staphylococcal toxins are a common cause of food poisoning. They are produced by bacteria growing in inadequately stored foods. Probably the most notorious organisms of the genus are methicillin-resistant Staphylococcus aureus (MRSA), bacteria responsible for several difficult-to-treat infections in humans. MRSA is any strain of Staphylococcus aureus that has developed resistance to beta-lactam antibiotics, which include the penicillins (methicillin, dicloxacillin, nafcillin, oxacillin, etc.) and the cephalosporins. They are believed to have emerged through the process of natural selection as a consequence of over-usage of antibiotics.