The Gram-positive pathogen Staphylococcus aureus remains one of the most problematic and costly sources of bacterial infection worldwide (Diekema

et al., 2001). Disease typically presents as mild skin/soft tissue infections but can also be the source of more serious bacteremia, endocarditis, osteomyelitis and necrotizing pneumonia (Lowy, 1998). Staphylococcus aureus asymptomatically colonizes the skin and, more commonly, the anterior nasal passages of healthy people (Foster, 2009). Nasal colonization is the most significant predictor of invasive disease; however, in some studies, nearly half of patients carrying S. aureus are strictly colonized extranasally (Schechter-Perkins et al., 2011). Thus, estimates of S. aureus carriage at ~ 25% of the human population may be an underestimate of true colonization levels. Given the near ubiquity of learn more S. aureus among the human population combined with its virulence potential, it is no Ruxolitinib mouse wonder this organism has been recognized as a significant healthcare burden for over a century. Staphylococcus

aureus was first described by Alexander Ogston in 1881 as the sole microorganism within the fluid drained from a severe knee abscess (Ogston, 1881). Then, he noted that ‘once established the micrococci are hard to kill…’ underscoring the recalcitrant nature of S. aureus toward antiseptic treatment (Newsom, 2008). During this time, Joseph Lister’s influence on surgical procedures through

the implementation of carbolic acid (phenol) Coproporphyrinogen III oxidase to sterilize wounds and instruments had greatly reduced the occurrence of post-operative infections (Lister, 1867). However, it was subsequently shown that S. aureus was inherently resistant to phenol explaining its association with surgical infections despite good ‘sterile technique’ (Reddish, 1925). Thus, S. aureus was recognized as an important hospital-associated pathogen over 130 years ago in the pre-antibiotic era and little has changed to this day. Perhaps because of its intimate association with hospitals and patients, S. aureus has always been among the first bacterial species reported to develop resistance to new antimicrobials, from sulfonamide resistance in the early 1940s (Landy et al., 1943) to the identification of penicillinase in 1944 (Kirby, 1944) just months after US penicillin production reached full scale. Interestingly, these progenitor β-lactamase positive S. aureus clones were isolated from patients that had not even been treated with penicillin. Nonetheless, penicillin-resistant S. aureus was here to stay and became pandemic in hospitals during the late 1950s and early 1960s (Rountree & Freeman, 1955). Subsequently, a penicillinase-resistant β-lactam derivative, methicillin (Celbenin; Beecham Pharmaceuticals), was approved for use in the US in 1959.