Management of MRSA infections: Updated UK Guidelines

Current UK guidelines for the treatment of MRSA are based on clinical evidence published more than 10 years ago. British Society for Antimicrobial Chemotherapy (BSAC) and British Infection Association (BIA) have developed an update to the previous recommendations, taking into account the changes in UK epidemiology of MRSA, ongoing national surveillance data and the efficacy of novel anti-staphylococcal agents licensed for use in the UK. Emerging therapies (new anti-staphylococcal antibiotics) that had not been licensed for use in the UK at that time of review (2008) were also included. They published their new recommendations in the JAC-Antimicrobial Resistance on February 03, 2021.
BSAC and BIA have jointly revised the following 13 sections which include:

1. Impetigo
2. Abscesses
3. Other skin and skin structure infections
4. Urinary tract infection (UTI)
5. Endocarditis
6. Nosocomial pneumonia
7. Eye infection
8. Bone and joint infections
9. Bacteraemia
10. Necrotizing pneumonia
11. Ear, nose and throat or upper respiratory tract infection
12. Intracranial or spinal infection and
13. Meningitis

• "To prevent the development of antimicrobial resistance, consider an alternative to topical fusidic acid or mupirocin, for example a topical antiseptic such as hydrogen peroxide 1% cream, to treat impetigo caused by MRSA where there is localized, non-bullous disease and the patient is clinically well. Consider topical fusidic acid or mupirocin as a second-line option in this clinical setting and only when the MRSA isolate is known to be susceptible (weak recommendation).

• Treat complicated impetigo using systemic antimicrobial therapy with the choice of agent determined by susceptibility testing (strong recommendation)."

• "Use incision and drainage to treat abscesses caused by MRSA.Do not use antibiotics routinely in patients with abscesses caused by MRSA that are drained, are less than 5 cm in diameter, and where there is no systemic response (fever and/or cellulitis) and/or immunodeficiency, including neutropenia and defects of cell-mediated immunity.

• Use antibiotics in combination with incision and drainage in patients with abscesses caused by MRSA PFGE strain type USA300, or where this is likely to be the most prevalent strain.

• Use oral clindamycin or co-trimoxazole when oral treatment is warranted, and the MRSA isolate is known to be susceptible.

• "For severe cellulitis/soft tissue infection caused by MRSA use intravenous glycopeptides (vancomycin or teicoplanin) (strong recommendation).

• Use linezolid (oral or intravenous) or daptomycin (intravenous) as an alternative (strong recommendation).

• Consider tigecycline as an alternative when first- and second-line agents are contraindicated, and the isolate is susceptible (weak recommendation).

• Consider clindamycin, co-trimoxazole, or doxycycline as oral agents (when the isolate is susceptible) for treatment of patients with mild skin and soft tissue infection caused by MRSA, or for oral stepdown therapy (weak recommendation).

• Consider recently licensed agents such as ceftaroline, delafloxacin, oritavancin, or telavancin as alternative options for treatment of cellulitis/soft tissue infection caused by MRSA (weak recommendation).

• No recommendations can be made on the use of ceftobiprole, dalbavancin and tedizolid over standard therapeutic agents in the treatment of SSTI caused by MRSA."

• Exclude the presence of MRSA bacteraemia before commencing treatment of MRSA isolated from urine.

• Consider treating a genuine lower UTI caused by MRSA with an oral agent, such as doxycycline, trimethoprim, ciprofloxacin, or co-trimoxazole, according to susceptibility.

• For complicated UTI caused by MRSA consider intravenous glycopeptides (vancomycin or teicoplanin) as the first-line treatment.

• When a glycopeptide is contraindicated consider daptomycin as an alternative agent if intravenous therapy is required .

• Linezolid is not recommended for the treatment of MRSA UTI, given its poor excretion by the kidney.

• For catheter-associated UTI caused by MRSA, whenever possible/practicable replace the catheter, with or without a single dose of gentamicin if the MRSA isolate is known to be susceptible (weak recommendation). Consider a single dose of glycopeptide (vancomycin or teicoplanin) as an alternative if the isolate is resistant to gentamicin or there are other contraindications.

• "Use a multidisciplinary approach for treatment of MRSA bone and joint infections, including surgery or drainage where indicated (strong recommendation).

• For bone and joint infections caused by MRSA use intravenous glycopeptides (vancomycin or teicoplanin) as the first-line choice of treatment (strong recommendation).

• Consider 2 weeks of intravenous glycopeptide (vancomycin or teicoplanin) followed by further intravenous or oral antibiotics to complete a total treatment course of a minimum of 4 weeks for septic arthritis or 6 weeks for osteomyelitis (weak recommendation).

• Use therapeutic drug monitoring to ensure that non-toxic, therapeutic pre-dose serum concentrations of 15–20 mg/L for vancomycin, or 20–40 mg/L for teicoplanin are achieved (strong recommendation).

• When a glycopeptide is contraindicated consider daptomycin (6 mg/kg dose) or linezolid as alternative agents (weak recommendation).

• Use clindamycin, co-trimoxazole, doxycycline, or linezolid as oral options to complete treatment when the MRSA isolate is known to be susceptible (strong recommendation).

• Do not use rifampicin, fusidic acid or a quinolone as a single oral agent; use in combination with other agents to which the isolate is susceptible (strong recommendation)."

• "Use intravenous vancomycin for uncomplicated bacteraemia caused by MRSA (strong recommendation).

• When vancomycin is contraindicated use linezolid as an alternative first-line choice of treatment (strong recommendation).

• When first-line agents are contraindicated consider daptomycin or teicoplanin (weak recommendation).

• Do not use co-trimoxazole alone as a first-line agent for MRSA bacteraemia, however, consider using it as an oral step-down when the MRSA isolate is known to be susceptible (weak recommendation).

• Consider a minimum duration of 14 days of antibiotic therapy for uncomplicated bacteraemia and a minimum duration of 28 days for complicated bacteraemia caused by MRSA (weak recommendation)."

• "In the absence of at least one additional randomized controlled trial (RCT) confirming the superiority of linezolid over vancomycin for nosocomial pneumonia caused by MRSA, ideally associated with a low risk of bias, we have opted to recommend either intravenous vancomycin or linezolid as first-line therapy (weak recommendation).

• Do not use daptomycin to treat nosocomial pneumonia caused by MRSA as it is inactivated by lung surfactant (strong recommendation).

• No recommendations can be made on the use of ceftobiprole over standard therapeutic agents in the treatment of HAP caused by MRSA."

• "For severe MRSA-associated ear, nose and throat or upper respiratory tract infections consider intravenous glycopeptide (vancomycin or teicoplanin) or linezolid.

• For minor/less-severe infections consider co-trimoxazole or doxycycline as an oral option when the MRSA isolate is known to be susceptible."

• "Whenever clinically possible, source control is necessary for intracranial and spinal infections (strong recommendation).

• Unless surgical intervention is contraindicated use incision and drainage for treatment of intracranial and spinal infections caused by MRSA (strong recommendation).

• In the absence of neurological deficits consider treating small epidural abscesses with antibiotics alone (weak recommendation).

• For treatment of intracranial and spinal infections caused by MRSA consider intravenous vancomycin or linezolid as the first-line choice of treatment (weak recommendation)."

• "Use intravenous vancomycin (strong recommendation). For severe infection, consider adding rifampicin according to susceptibility (weak recommendation).

• Use therapeutic drug monitoring to ensure that non-toxic, therapeutic pre-dose serum concentrations (15–20 mg/L) of vancomycin are achieved (strong recommendation).

• In severe cases, or when the patient fails to respond to intravenous vancomycin, patients should be transferred to a neurosurgical centre for instillation of vancomycin directly into the ventricles (strong recommendation).

• Do not use clindamycin, chloramphenicol or linezolid to treat meningitis caused by MRSA (strong recommendation). These drugs are not bactericidal, such activity being a requirement of antibiotics used as therapy of patients with meningitis.

• No recommendation can be made for the use of teicoplanin in this clinical setting."

• "For superficial MRSA eye disease consider gentamicin or chloramphenicol eye drops according to isolate susceptibility (weak recommendation).

• Consider dissemination secondary to bacteraemia when a patient is diagnosed with endophthalmitis caused by MRSA (strong recommendation).

• For deep-seated eye infections caused by MRSA consider a multidisciplinary approach comprising specialist ophthalmologists and infection specialists (weak recommendation).

• For deep-seated eye infections caused by MRSA consider intravitreal vancomycin and systemic quinolones according to susceptibility (weak recommendation).

• Consider oral linezolid as a treatment option, recognizing that there is limited evidence of efficacy in MRSA infection at this site (weak recommendation)."