engleski

Tetracycline and chloramphenicol resistance in methicillin-resistant Staphylococcus pseudintermedius (MRSP)

Tetracycline and chloramphenicol resistance in methicillin-resistant Staphylococcus pseudintermedius (MRSP) Background: Methicillin-resistant Staphylococcus pseudintermedius (MRSP) is emerging as a significant pathogen in veterinary medicine. MRSP strains are often resistant to many non-betalactam antimicrobials, such as gentamicin, lincomycin, clindamycin, erythromycin, fluoroquinolones and trimetoprim/sulphametoxazol. In addition, about 70% of MRSP isolates were found to be resistant to tetracycline and 57% to chloramphenicol, thereby further limiting the panel of therapeutically useful antimicrobial agents. These two antimicrobials are the only drugs labeled for veterinary use in Croatia that might still be effective for treatment of MRSP infections. Objectives: The aim of this study was to determine the minimum inhibitory concentrations (MIC) of tetracycline and chloramphenicol against 34 MRSP strains isolated from dogs and cats in Croatia and to reveal the genetic basis of resistance. Methods: MICs of tetracycline and chloramphenicol were determined by gradient diffusion (E-test®, bio-Merieux, France) on Müller-Hinton agar at 37ºC. The presence of tetracycline (tetM and tetK) and chloramphenicol (catpC221) resistance genes was examined by PCR. Conclusions: Eight (23.5%) and 17 (50%) out of 34 MRSP strains were resistant to tetracycline and chloramphenicol, respectively. tetK gene was detected in 6 and tetM in 2 isolates. All chloramphenicol resistant strains carried the catpC221 gene. The tetracycline resistance rate in Croatian strains is significantly lower than in European isolates, indicating tetracycline can be considered for treatment in most cases when systemic therapy is needed. References: PERRETEN, V. et al. (2010): Clonal spread of methicillin-resistant Staphylococcus pseudintermedius in Europe and North America: an international multicentre study. J. Antimicrob. Chemother. 65, 1145-1154.

methicillin-resistant Staphylococcus pseudintermedius; tetracycline; chloramphenicol; resistance

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