Community Acquired MRSA Health TopicsNewsDataPrograms Publications Site Map This MRSA health advisory is being sent to you in response to inquiries from primary care providers expressing a concern over the number of MRSA cases that they are seeing in their practices. (S. aureus) bacteria are resistant to antibiotics. MRSA is a type of S. areus that is resistant to antibiotics called beta-lactams. Beta-lactam antibiotics include methicillin and other more common antibiotics such as oxacillin, penicillin and amoxicillin. Most healthcare-associated MRSA (HA-MRSA) are also resistant to macrolides, fluoroquinolones, clindamycin, and trimethoprim/sulfamethoxazole, While 25% to 30% of the population is colonized with S. aureus overall, only 1% are colonized with MRSA. I n the US, HA-MRSA has been a long-standing problem. HA-MRSA is also commonly seen in hospitals and in long-term care facilities and in US hospitals, 52% of S. aureus isolates recovered from patients in ICUs and 42% of S. aureus recovered from non-ICU patients are MRSA. After obtaining appropriate cultures, treat with empiric oral antibiotics for infections such as large or multiple furuncles, soft-tissue abscesses, cellulitis, deep-seated folliculitis, impetigo, ecthyma. If no MRSA risk factors: consider such antibiotics as dicloxacillin, cephalexin or amoxicillin/clavulanate. In context of an MRSA outbreak or presence of MRSA risk factors, treat with: TMP/SMX + rifampin. Treat with clindamycin rather than TMP/SMX if streptococcal infection is in the differential diagnosis. However, some MRSA isolates can become resistant to clindamycin while on therapy (i.e., inducible clindamycin resistance) and this should be suspected if a CA-MRSA isolate is erythromycin-resistant. Thus, an alternative to clindamycin (e.g. high-dose levofloxacin) should be considered for erythromycin-resistant isolates.
