Staphylococci in orthopaedic surgical wounds

Area of Science:

• Infectious Diseases
• Clinical Microbiology
• Orthopaedic Surgery

Background:

• Staphylococcal infections are a common complication in orthopaedic surgical wounds.
• Methicillin resistance in staphylococci is a growing global health concern.
• Coagulase-negative staphylococci are increasingly recognized as significant pathogens.

Purpose of the Study:

• To determine the prevalence of staphylococcal species in infected orthopaedic surgical wounds.
• To assess the rate of methicillin resistance in isolated staphylococcal strains, including Staphylococcus aureus and coagulase-negative staphylococci.
• To identify the presence of the mecA gene in methicillin-resistant strains.

Main Methods:

• Bacterial isolation and identification from 50 infected orthopaedic surgical wounds.
• Agar disk diffusion testing for methicillin resistance screening.
• Polymerase Chain Reaction (PCR) for the detection of the mecA gene.

Main Results:

• Staphylococci were isolated from 86% of wounds, with Staphylococcus aureus being the most prevalent (68% of all isolates).
• Methicillin resistance was observed in 32% of Staphylococcus aureus and 33% of Staphylococcus epidermidis strains.
• The mecA gene was confirmed in all methicillin-resistant isolates, indicating true resistance.

Conclusions:

• Staphylococci, particularly Staphylococcus aureus, are the predominant pathogens in orthopaedic surgical site infections.
• A significant proportion of both Staphylococcus aureus and coagulase-negative staphylococci strains exhibit methicillin resistance.
• The findings highlight the urgent need for surveillance and control strategies against methicillin-resistant staphylococci in surgical settings.