Korean J Infect Dis.  2002 Dec;34(6):367-372.

Evaluation of CHROMagar Staph aureus, a New Chromogenic Medium, for the Detection of Nosocomial Methicillin-Resistant Staphylococcus aureus

• Lee H

Abstract

BACKGROUND
Staphylococcus aureus remains one of the most frequently encountered bacterial pathogens and is responsible for a variety of mild to life- threatening infections. There is a substantial body of evidence that individuals who are asymptomatic nasal carriers of S. aureus are at increased risk of developing serious staphylococcal infections. Approximately 20% to 30% of health care workers at any given time are also nasal carriers of S. aureus. A subset of these may spread the organism to patients by direct contact transmission. CHROMagar Staph aureus (CSA) is a new chromogenic medium for identification of S. aureus on the basis of colony pigmentation.
METHODS
The abilities of CSA, thermostable nuclease (DNase), and mannitol salt agar (MSA) to identify S. aureus isolates (n=70) and discriminate between S. aureus and coagluase-negative staphylococci (CoNS; n=8) were compared.
RESULTS
CSA proved to be more sensitive and specific than DNase and MSA, allowing a reliable, simple, and rapid method for the identification of S. aureus isolates. All CoNS encountered in this study could be easily differentiated from S. aureus on the medium. The supplementation with 4 microgram/mL of oxacillin allowed simple identification of methicillin resistance in hospital acquired S. aureus strains which show multiple drug resistance profiles.
CONCLUSION
CSA proved to be simple and reliable method for the identification of nasal carriers of S. aureus of health care workers.

Keyword

CHROMagar Staph aureus; Methicillin-resistant Staphylococcus aureus

MeSH Terms

Agar
Delivery of Health Care
Deoxyribonucleases
Drug Resistance, Multiple
Humans
Mannitol
Methicillin Resistance*
Methicillin-Resistant Staphylococcus aureus*
Micrococcal Nuclease
Oxacillin
Pigmentation
Staphylococcal Infections
Staphylococcus aureus
Agar
Deoxyribonucleases
Mannitol
Micrococcal Nuclease
Oxacillin