Thermo Scientific™ Mueller Hinton Agar w/4% NaCl, 6μg/mL Oxacillin

Description

• Screen Staphylococcus aureus for resistance to penicillinase-resistant penicillins (PRP) (e.g., methicillin, nafcillin and oxacillin) with Thermo Scientific™ Remel™ Mueller Hinton Agar w/4% NaCl, 6 μg/mL Oxacillin
• Methicillin, a penicillinase-resistant penicillin (PRP) was introduced in 1960 as a therapeutic agent active against β-lactamase-producing strains of S
• aureus
• Soon after, Methicillin-resistant S
• aureus (MRSA) was reported in Great Britain and continues to be one of the leading causes of nosocomial infections worldwide
• 1-3 Mueller Hinton Agar w/4% NaCl, 6 μg/mL Oxacillin (MRSA Screen) is a solid medium recommended for use in screening of Staphylococcus aureus for antibiotic susceptibility testing to determine resistance to PRP’s
• MRSA strains are referred to as heteroresistant because resistant as well as susceptible subpopulations coexist within a culture
• The resistant population usually grows much more slowly than the susceptible subpopulation leading to detection problems with traditional in vitro susceptibility test methods
• Successful detection of MRSA therefore depends on promoting the growth of the resistant subpopulation, which favors lower temperatures, longer incubation, and the presence of salt in the media
• Amongst the anti-staphylococcal β-lactamase-stable penicillins, oxacillin can be tested and the results applied to other penicillin-stable penicillins such as cloxacillin and dicloxacillin
• Ready-to-use – Convenience of prepared media
• Easy to interpret – Growth of > 1 colony indicates Resistant (MRSA) strain whereas no growth or 1 colony indicates Susceptible (not MRSA)
• Mueller Hinton Agar w/4% NaCl, 6μg/mL Oxacillin contains beef extract and acid hydrolysate of casein which supply amino acids, nitrogenous substances, vitamins and minerals necessary for growth
• Starch acts as a protective colloid against toxic materials present in the medium
• The inclusion of starch in the medium ensures that toxic factors produced during microbial growth will be absorbed, and its presence is often essential to establish growth from very small inocula
• Sodium chloride is added since it helps in better growth of methicillin-resistant S
• aureus
• Agar is the solidifying agent
• Of the available β-lactamase-stable penicillins, oxacillin is preferred because it is more resistant to degradation in storage and it easily detects heteroresistant staphylococcal strains 4
• Not all products are available for sale in all territories
• Please inquire
• Remel™ and Oxoid™ products are now part of the Thermo Scientific brand.