What is the treatment for persistent Methicillin-resistant Staphylococcus aureus (MRSA) infection in the groin area?

From the Guidelines

For persistent MRSA in the groin area, I strongly recommend incision and drainage as the primary treatment, followed by antibiotic therapy, as the area is difficult to drain and has a high risk of complications, as suggested by the guidelines 1. When dealing with persistent MRSA infections in the groin area, it's essential to consider the unique challenges posed by this location, including warmth, moisture, and skin folds that create an ideal environment for bacterial persistence.

• The guidelines suggest that for abscesses in areas difficult to drain, such as the genitalia, antibiotic therapy is recommended in addition to incision and drainage 1.
• The recommended antibiotic options for empirical coverage of CA-MRSA in outpatients with SSTI include clindamycin, TMP-SMX, a tetracycline (doxycycline or minocycline), and linezolid 1.
• For hospitalized patients with complicated SSTI, empirical therapy for MRSA should be considered pending culture data, with options including IV vancomycin, linezolid, daptomycin, telavancin, and clindamycin 1.
• In addition to antibiotic therapy, proper hygiene and wound care are crucial in managing persistent MRSA infections, including daily chlorhexidine washes or bleach baths, applying mupirocin 2% ointment to the affected area, and ensuring the area remains dry and clean.
• It's also important to note that persistent MRSA colonization often requires a multi-faceted approach, as the bacteria can form biofilms and develop resistance to single treatments, and if these measures fail after 2-3 weeks, consultation with an infectious disease specialist may be necessary.

From the FDA Drug Label

The cure rates by pathogen for microbiologically evaluable patients are presented in Table 18. Table 18 Cure Rates at the Test-of-Cure Visit for Microbiologically Evaluable Adult Patients with Complicated Skin and Skin Structure Infections Pathogen Cured ZYVOX n/N (%) Oxacillin/Dicloxacillinn/N (%) Methicillin-resistant S aureus 2/3 (67) 0/0 (-)

A separate study provided additional experience with the use of ZYVOX in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections. The cure rates in microbiologically evaluable patients with MRSA skin and skin structure infection were 26/33 (79%) for linezolid-treated patients and 24/33 (73%) for vancomycin-treated patients

Table 19 Cure Rates at the Test-of-Cure Visit for Microbiologically Evaluable Adult Patients with Diabetic Foot Infections Pathogen Cured ZYVOX n/N (%) Comparatorn/N (%) Methicillin-resistant S aureus 12/17 (71) 2/3 (67)

The cure rates for MRSA infections were:

• 67% (2/3) in complicated skin and skin structure infections
• 79% (26/33) in MRSA skin and skin structure infection
• 71% (12/17) in diabetic foot infections Based on these cure rates, linezolid may be effective in treating MRSA infections, including those in the groin area. However, it is essential to note that the groin area is not explicitly mentioned in the studies, and the effectiveness of linezolid for this specific location is not directly addressed. 2

From the Research

Treatment Options for Persistent MRSA Infections

• Vancomycin and daptomycin are commonly used to treat MRSA infections, but treatment outcomes can be poor due to limitations such as poor tissue penetration and emerging resistance 3, 4.
• Combination antibiotic therapy has been explored as an alternative, but results have been inconsistent, with some combinations showing antagonistic or indifferent effects 3.
• However, some studies suggest that combination therapy with β-lactam antibiotics, such as ceftaroline, may be effective in treating persistent MRSA infections 5, 6.
• Other treatment options for persistent MRSA infections include high-dose daptomycin, trimethoprim-sulfamethoxazole, fosfomycin, linezolid, and telavancin, often used in combination with other antibiotics 6.
• A case study also reported the successful use of a combination of daptomycin, vancomycin, and rifampin to treat recurrent MRSA bone and prosthetic joint infections 7.

Considerations for Treatment

• The choice of treatment should take into account factors such as recent antibiotic exposure, source control, and available synergy and clinical data 6.
• Randomized controlled trials are needed to establish a preferred treatment regimen and create a universal treatment algorithm for persistent MRSA infections 5, 6.
• Current guidelines recommend evaluation and removal of possible sources of infection, as well as consideration of a change in therapy, when MRSA bacteremia persists despite adequate initial treatment 6.