Published in Scientific Works. Series C. Veterinary Medicine, Vol. LXIV, Issue 1
Written by N. CĂTANA, Iulia BUCUR, Corina PASCU, V. HERMAN
In the last years, an increasing attention is paid to methicillin-resistant staphylococci, isolated from animals, regardless of the species they are included in. The circulation of methicillin-resistant staphylococci strains is monitored by phenotypic laboratory techniques or with several chromogenic media. The frequency of methicillin-resistant strains was pursued on 412 strains included in S. aureus subsp. aureus and other species from the "non-S. aureus" group, based on phenotypic characters. Using the disc-diffusion method with methicillin, oxacillin and cefoxitin, 210 strains resistant to methicillin were identified and poured into a chromogenic medium named ChromaticTM MRSA. On this medium, S. aureus subsp. aureus strains resistant to at least one of the three antibiotics, formed purple to purpleorange colonies and the “non-S. aureus” strains formed white or blue colonies. All S. aureus subsp. aureus strains on this medium were methicillin-resistant, results identical to the disc-diffusion method ones. 146 “non-S. aureus” strains formed white or blue colonies, considered as methicillin-resistant, while 6 strains did not grow on this medium.
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