Antimicrobial susceptibility patterns and characterization of clinical isolates of Staphylococcus aureus in immunocompromised cancer patients undergoing chemotherapy in Pakistan.

ABSTRACT

Cancer patients undergoing chemotherapy are highly prone to infections because of suppression of their immune system. in the present study, the activity of fluoroquinolones, cephalosporins, glycopeptides and oxazolidinones was evaluated in Staphylococcus aureus strains by broth dilution method according to Clinical and laboratory Standards institute (ClSi), USA guidelines. the frequency of methicillin-resistant S. aureus (mRSA) and methicillin-sensitive S. aureus (mSSA) strains was 67% and 33% respectively. The MIC(50 )and MIC(90 )of isolates were ciprofloxacin 8 and 32 microg/ml for mRSA, 8 and 16 microg/ml for mSSA, levofloxacin 8 and 16 microg/ml for mRSA and mSSA, gatifloxacin 4 and 16 microg/ml for mRSA and 4 and 8 microg/ml for mSSA. MIC(50 )and MIC(90 )of vancomycin and linzolid were 1 and 2 microg/ml, 2 and 4 microg/ml for both mRSA and mSSA strains respectively. this study shows a high prevalence of and resistance in mRSA. However, vancomycin and linezolid were highly active and could be used for treating mRSA infections.