title: Susceptibility of methicillin-resistant Staphylococci clinical isolates to netilmicin and other antibiotics commonly used in ophthalmic therapy.
abstract: OBJECTIVE
  The aim of this study was to test the activity of selected antimicrobial agents commonly used in the treatment of ocular infections against methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE) isolates.
  
  
  METHODS
  A total of 43 staphylococci from respiratory tract and ocular infections were characterized for methicillin resistance using the Epsilometer test (E-test), the polymerase chain reaction for mecA gene detection and the PBP2' latex agglutination test. A perfect agreement among them was observed in 20 isolates (8 MRSA and 12 MRSE) which were then employed in the susceptibility test by using the agar disk diffusion test (NCCLS). The antibiotics tested were: netilmicin (NET), tobramycin (TOB), azithromycin (AZM), levofloxacin (LEV), moxifloxacin (MXF), chloramphenicol (C) and vancomycin (VA).
  
  
  RESULTS
  All MRSE and most (87.5%) of MRSA isolates tested were NET and VA sensitive. The majority of MRSA were found to be resistant to all the other antibiotics, with the exception of C. In particular, 75%, 87% and 100% of the isolates were resistant to fluoroquinolones (LEV and MXF), AZM and TOB, respectively. As for the MRSE group, 25% of the strains tested were resistant to C and MXF while 33%, 42% and 58% of the strains were resistant to LEV, AZM and TOB, respectively.
  
  
  CONCLUSIONS
  Together with VA, NET was the most effective antibiotic tested against both MRSA and MRSE clinical isolates. The exclusive topical use of NET for the treatment of ocular infections may curtail the emergence, spreading and persistence of antibiotic-resistant bacteria.
authors.affiliation: Research & Development, S.I.F.I. SpA, Aci S. Antonio (CT), Italy. rita.blanco@sifigroup.com
authors.forename: Anna Rita
authors.initials: AR
authors.lastname: Blanco
authors.forename: Andrea
authors.initials: A
authors.lastname: Sudano Roccaro
authors.forename: Carmela Giovanna
authors.initials: CG
authors.lastname: Spoto
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Papa
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001372:Aza Compounds / Q000494:pharmacology; D017963:Azithromycin / Q000494:pharmacology; D002701:Chloramphenicol / Q000494:pharmacology; D004351:Drug Resistance / Q000235:genetics*; D015818:Eye Infections, Bacterial / Q000188:drug therapy*; D024841:Fluoroquinolones; D006801:Humans; D064704:Levofloxacin / Q000494:pharmacology; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics; D008826:Microbial Sensitivity Tests; D000077266:Moxifloxacin; D009428:Netilmicin / Q000494:pharmacology*; D011804:Quinolines / Q000494:pharmacology; D013212:Staphylococcus epidermidis / Q000187:drug effects* / Q000235:genetics; D014031:Tobramycin / Q000494:pharmacology; D014640:Vancomycin / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D011804:Quinolines; D009428:Netilmicin; D002701:Chloramphenicol; D064704:Levofloxacin; D014640:Vancomycin; D017963:Azithromycin; D000077266:Moxifloxacin; D014031:Tobramycin