Comparison of five usual techniques for detection of methicillin-resistant Staphylococcus aureus

The detection of methicillin-resistant Staphylococcus aureus in an usual and daily lest in a microbiology laboratory. But its interpretation isn't easy because the resistance expression in vitro is so variable. The authors compare five methods about 100 clinical isolated strains. The results are: disk diffusion method using oxacillin 5 mug, on a NaCl 5 % Mueller Hinton agar, 100 ml presentation, (biorad(R)): specificity 91 %; disk diffusion method using oxacillin 5 mug, on a NaCl 5 % Mueller Hinton agar, ready to use plate (AES(R)): specificity 95 %; the Oxascreen agar (BD(R)): specificity 96 %; the oxacillin cupule of ATB STAPH strip (ATB expression bioMerieux(R) system) NaCl 2 % semi solid Mueller Hinton agar medium: specificity 100 %; disk diffusion method using cefoxitin 30 mug, on a Mueller Hinton agar plate (bioMerieux(R)): specificity 100 %. Therefore the cefoxitin disk diffusion method is very interesting to make better the difference between methicillin-resistant and methicillin-sensible S. aureus, in association with the ATB STAPH(R) strip. (C) 2004 Elsevier SAS. Tous droits reserves.