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 fluoro-quinolones, 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 MIC₅₀ and MIC₉₀ of isolates were ciprofloxacin 8 and 32 μg/ml for MRSA, 8 and 16 μg/ml for MSSA, levofloxacin 8 and 16 μg/ml for MRSA and MSSA, gatifloxacin 4 and 16 μg/ml for MRSA and 4 and 8 μg/ml for MSSA. MIC₅₀ and MIC₉₀ of vancomycin and linzolid were 1 and 2 μg/ml, 2 and 4 μg/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.

Keywords:

• Staphylococcus aureus infections
• cancer patients
• methicillin-resistant Staphylococcus aureus
• antimicrobial resistance