Growing Resistance to Vancomycin among Methicillin Resistant Staphylococcus Aureus Isolates from Different Clinical...

Area of Science:

• Clinical microbiology
• Infectious diseases
• Antimicrobial resistance

Background:

• Methicillin-resistant Staphylococcus aureus (MRSA) poses a significant global threat in healthcare settings.
• Increasing antibiotic resistance in MRSA strains complicates treatment options.
• This study investigates MRSA resistance patterns and vancomycin susceptibility in Nepal.

Purpose of the Study:

• To analyze the antimicrobial resistance profile of MRSA isolates.
• To determine the minimum inhibitory concentration (MIC) of vancomycin against MRSA.
• To assess the prevalence of MRSA in clinical samples at KIST Medical College and Hospital.

Main Methods:

• Processed 3500 clinical samples (blood, urine, body fluids).
• Identified S. aureus and screened for methicillin resistance using cefoxitin disk diffusion.
• Determined vancomycin MIC in MRSA isolates via agar dilution method (CLSI guidelines).

Main Results:

• Isolated 287 S. aureus strains; 42 (14.63%) were MRSA.
• All MRSA isolates exhibited resistance to ampicillin and penicillin.
• Four MRSA isolates showed intermediate vancomycin MIC, despite sensitivity on disk diffusion.

Conclusions:

• Elevated vancomycin MIC in MRSA is a critical concern.
• Urgent implementation of MRSA control measures is necessary.
• Routine surveillance for vancomycin-resistant Staphylococcus aureus (VRSA) is essential in hospitals.