Why is nafcillin better than vancomycin for MSSA?

Growth in the presence of sub-inhibitory nafcillin significantly enhanced LL-37 killing of MSSA compared to vancomycin and antibiotic-free controls. Nafcillin also reduced MSSA production of the golden staphylococcal pigment staphyloxanthin in 39% of pigmented strains vs. 14% for vancomycin.

Why is vancomycin not used for MSSA?

Vancomycin is associated with higher rates of infection-related mortality, re-infection and bacteriologic failure compared to cloxacillin or cefazolin in the definitive treatment of MSSA bacteremia [9, 12–15].

Is vancomycin effective against MSSA?

Background: Previous studies indicate that vancomycin is inferior to beta-lactams for treatment of methicillin-susceptible Staphylococcus aureus (MSSA) bloodstream infections. However, it is unclear if this association is true for empiric and definitive therapy.

Is MRSA susceptible to nafcillin?

What is the treatment for MRSA? Although MRSA cannot be effectively treated with antibiotics such as methicillin, nafcillin, cephalosporin or penicillin, it can usually be treated with an antibiotic called vancomycin.

Does vancomycin treat MRSA?

Treatment options for health care–associated MRSA or community-associated MRSA pneumonia include seven to 21 days of intravenous vancomycin or linezolid, or clindamycin (600 mg orally or intravenously three times per day) if the strain is susceptible.

What is MSSA vs MRSA?

Those that are sensitive to meticillin are termed meticillin-sensitive Staphylococcus aureus (MSSA). MRSA and MSSA only differ in their degree of antibiotic resistance: other than that there is no real difference between them. Having MSSA on your skin doesn’t cause any symptoms and doesn’t make you ill.

Does vancomycin cover MRSA?

Vancomycin or daptomycin are the agents of choice for treatment of invasive MRSA infections [1].

How is MSSA treated?

Most MSSA infections can be treated by washing the skin with an antibacterial cleanser, using warm soaks, applying an antibiotic ointment prescribed by a doctor, and covering the skin with a clean dressing. Doctors also may prescribe oral antibiotics to treat MSSA infections.

Why vancomycin is preferred for MRSA?

Currently, vancomycin is generally used for infections caused by MRSA and for the treatment of patients allergic to semisynthetic penicillin or cephalosporins [13]. Vancomycin exerts its bactericidal action via interrupting proper cell wall synthesis in the susceptible bacteria.

Why is vancomycin the drug of choice for MRSA?

A glycopeptide with antistaphylococcal activity, vancomycin disrupts cell wall synthesis and arrests bacterial growth. Vancomycin rapidly became the mainstay for the treatment of beta-lactam-resistant gram-positive infections, especially those due to MRSA.

Which is worse MRSA or MSSA?

These are called methicillin-resistant staph (MRSA), as opposed to methicillin-susceptible staph (MSSA). In terms of global health, MRSA is a more serious problem than MSSA because of its ability to evolve. There are even a few strains that can resist vancomycin, one of the last remaining antibiotics for MRSA.

Is MRSA more virulent than MSSA?

Numerous clinical studies have indicated, based on mortality rates, that methicillin-resistant Staphylococcus aureus (MRSA) strains are more virulent than methicillin-susceptible S. aureus (MSSA) strains.

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