Chromagar Staph aureus Versus Blood Agar and Mannitol Salt Agar ...

Egyptian Journal of Medical Microbiology, January 2007 Vol. 16, No. 1the interpretation of the observer or to a truediscoloration after prolonged incubation.Whatever the cause may be, we recommendreading CSA plates after 24 h, as this gives amore accurate result. (13)The cost of CSA is higher than that ofnonselective conventional media. However,there is some efficiency gained with the useof this medium. The more rapid visualizationof the specific mauve pigmentation ofS. aureus allows working through culturesmore quickly; therefore, slide coagulase testscan be substantially reduced or eliminated.Additional biochemical tests or identificationmethods that may be needed on occasion forfinal identification can also be reduced oreliminated. Moreover, there is no need tosubculture organisms for antimicrobialsusceptibility testing. (13)The cost of selective media such asMSA is higher than that of nonselectivemedia. The additional costs incurred with theuse of the MSA and required subcultureplates, slide coagulase, and additionalbiochemical tests narrow the cost differentialand make the change from a selectivemedium to CSA closer to cost-neutral. (12,13)So we recommend the use of CSAagar medium for the isolation and the specificidentification of S.aureus from pyodermalsuppurative skin lesions.REFERENCES1. Paule SM, Pasquariello AC, Hacek DM,Adrienne G. Fisher AG, ThomsonRB,Kaul KL, Peterson LR. Directdetection of Staphylococcus aureus fromadult and neonate nasal swab specimensusing real-time polymerase chainreaction. JMD 2004; 6(3):191-203.2. Philppe P, Michele B, Gerand L,Vandenesch F, Brun Y, Etienne J E.Comparative performances of sixagglutination kits assessed by usingtypical and atypical strains ofStaphylococcus aureus. J Clin Microbiol1997; 35:1138-40.3. Griethuysen V, Bes M, Etienne J,Zbinden R, Kluytmans J. Internationalmulticenter evaluation of latexagglutination tests for identification ofStaphylococcus aureus. J Clin Microbiol2001; 39:86-9.4. Perry JD, Rennison C, Butterworth LA,Hopley ALJ, F. Gould K. Evaluation ofS. aureus ID, a New Chromogenic AgarMedium for Detection of Staphylococcusaureus. J Clin Microbiol 2003; 41:5695-8.5. Merlino J, Leroi M, Bradbury R, VealD, Harbour C. New chromogenicidentification and detection ofStaphylococcus aureus and methicillinresistantS. aureus. J Clin Microbiol2000; 38:2378-80.6. Baumert N, Eiff CV, Schaaff F, PetersSG, Proctor RA, Sahl HG. Physiologyand antibiotic susceptibility ofStaphylococcus aureus small colonyvariants. Microb Drug Resist 2002;8:253-60.7. Baird R M, Lee WH. Media used in thedetection and enumeration ofStaphylococcus aureus. Int J FoodMicrobiol 1995; 26:15-24.8. Gaillot O, Wetsch M, Fortineau N,Berche P. Evaluation of CHROMagarStaph. aureus, a new chromogenicmedium, for isolation and presumptiveidentification of Staphylococcus aureusfrom human clinical specimens. J ClinMicrobiol 2000; 38:1587-91.9. Göran H , Fang H. Evaluation of TwoNew Chromogenic Media, CHROMagarMRSA and S. aureus ID, for IdentifyingStaphylococcus aureus and ScreeningMethicillin-Resistant S. aureus. J ClinMicrobiol 2005; 34:4242-4.10. Kloose WE, Bannerman TL.Staphylococcus and Micrococcus. In:Murray PR, Baron EJ, Pfaller MA,Tenover FC, Yoken RH (editors).Manual of clinical MICROBIOLOGY.6 th ed. Washington DC: Americansociety for Microbiology; 1995.p.282-98.11. Carricajo A, Treny A, Fonsale N, BesM, Reverdy M, Gille Y,et al,. Aubert,and A. M. Freydiere. Performance of thechromogenic medium CHROMagarStaph aureus and the Staphychromcoagulase test in the detection andidentification of Staphylococcus aureusin clinical specimens. J Clin Microbiol2001; 39:2581-3.12. D’Souza HA,Baron EJ. BBLCHROMaga Staph aureus is superior tomannitol salt for detection ofStaphylococcus aureus in complex66