Multidrug Resistance and mupA-Mediated Mupirocin Resistance in Clinical Coagulase-Negative Staphylococci

Area of Science:

• Clinical microbiology
• Infectious diseases
• Antimicrobial resistance

Background:

• Coagulase-negative staphylococci (CoNSs) are leading opportunistic pathogens in healthcare settings.
• Immunocompromised individuals and those with medical devices are particularly vulnerable to CoNS infections.
• Increasing antimicrobial resistance and biofilm formation by CoNS pose substantial clinical challenges.

Purpose of the Study:

• To investigate the species distribution of clinical CoNS isolates.
• To determine the antimicrobial resistance patterns, resistance genes, and biofilm production capabilities of these isolates.
• To assess the clinical relevance of multidrug-resistant, mupirocin-resistant, and biofilm-forming CoNS.

Main Methods:

• Analysis of 148 clinical CoNS isolates.
• Species identification and antimicrobial susceptibility testing.
• Detection of specific resistance genes (e.g., mecA, mupA, dfrA, dfrG) using molecular methods.
• Assessment of biofilm production capabilities.

Main Results:

• Staphylococcus epidermidis (49.3%) was the most common species, followed by S. hominis (27.0%) and S. capitis (6.8%).
• High resistance rates were observed for penicillin (83.8%), erythromycin (72.3%), cefoxitin (66.2%), fusidic acid (60.8%), and clindamycin (45.3%).
• The mecA gene was present in 69.5% of penicillin/cefoxitin-resistant isolates. 64.9% of isolates were biofilm super-producers, with no significant correlation to antibiotic resistance.

Conclusions:

• CoNS isolates exhibit significant multidrug resistance and high rates of biofilm formation.
• The prevalence of resistance genes like mecA underscores the challenge in treating CoNS infections.
• Findings emphasize the critical need for enhanced surveillance and infection control strategies against resistant CoNS in healthcare environments.