Methicillin resistance in Staphylococcus aureus infections among patients colonized with methicillin-susceptible Staphylococcus aureus

Abstract

Among patients with SA infection, the odds of the infection being an MRSA infection are 125-times lower in an MSSA carrier than in an MRSA carrier.

BODIPYs bearing a dimethylaminopropoxy substituent for imaging and photodynamic inactivation of bacteria

“…Also, the resistance can be increased by the use of antibiotics for multiple purposes in the husbandry of livestock [2]. The Gram-positive bacteria Staphylococcus aureus has been recognized as one of the pathogens with the highest epidemiological resistance found in hospital treatments [3]. Consequently, this microorganism represents a serious threat to medicine in health care.…”

Are methicillin-susceptible Staphylococcus aureus carriers protected from methicillin-resistant Staphylococcus aureus infections?

“…In this issue of CMI a study by Shrestha et al [13] implies that MSSA carriers are protected from MRSA infections. Shrestha et al studied the association between staphylococcal carriage status and methicillin-resistant S. aureus (MRSA) infections by assessing over 90,000 hospitalizations in the Cleveland Clinic Health system where S. aureus carriage status was predetermined.…”

“…Interestingly, Shrestha et al [13] report that MRSA infections occurred in about 50% of non-carriers who became infected. This proportion probably reflects the colonization pressure of MRSA in those hospitals: i.e., non-colonized patients are prone to developing an MRSA or MSSA infection depending on the hospital S. aureus population, as has been suggested previously [14].…”

“…Since Shrestha et al [13] did not include the non-infected patients in their calculations, their study is limited to defining the odds of an infected patient having been an MSSA carrier, but their data cannot truly imply that the odds of an MSSA carrier developing MRSA infection are significantly lower than that of a non-MSSA carrier. Nor can they imply that being an MSSA carrier is truly protective against MRSA infection.…”

“…The study of Shrestha et al [13] raises the question of the potential clinical implications for a patient being an MSSA carrier, but leaves unanswered questions. Does MSSA carriage protect from MRSA infection and from worse outcomes?…”