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. Author manuscript; available in PMC: 2017 Dec 18.
Published in final edited form as: Clin Infect Dis. 2014 Jan 22;58(9):1287–1296. doi: 10.1093/cid/ciu043

Table 5.

Summary of Studies Demonstrating Clinical Response of Staphylococcus Species and β-Lactams

Study Isolate Infection AST Result Initial Antimicrobial Therapy Outcome Source
MSSA
2 MSSA (294 pts) Bacteremia Not specified β-lactams (267 pts) or vancomycin (27 pts) Mortality rate was significantly higher in the vancomycin-treated group compared to the β-lactam–treated group [76]
3 MSSA (123 pts) Bacteremia Susceptibility testing for cephems not performed Cefazolin (46 pts) or vancomycin (77 pts) Cure rate of 91.3% from cefazolin and 83.1% from vancomycin [77]
MRSA
1

  1. MRSA (17 pts)

  2. MRSA (3 pts)

  1. Septicemia or endocarditis

  2. Endocarditis

 Susceptible to cephalothin, cephaloridine, and cephalexin by DD (25–30 mm zone) using Mueller-Hinton agar

  1. Cephalosporin (cephalothin, cephaloridine, cephalexin) ± aminoglycoside

  2. Cephalosporin (cephalothin, cephaloridine, cephalexin)

  1. All blood cultures continue to be positive until therapy changed

  2. All 3 patients died

 [54]
2 MRSA (7 pts)

  1. Empyema

  2. Empyema

  3. Osteomyelitis

  4. Bacteremia

  5. Pneumonia

  6. Wound infection

  7. Bacteremia

 All isolates tested had cephalothin MICs ranging from 0.25 to 32 µg/ mL. All strains were considered susceptible to cephalothin. Actual MICs were not specified.

  1. Gentamicin, cefazolin

  2. Cefazolin

  3. Cefazolin

  4. Cephalothin, gentamicin, vancomycin

  5. Gentamicin, cefazolin

  6. Cefazolin

  7. Cefazolin

 4/7 patients died [57]
3 MRSA (10 pts) Bacteremia Resistant to cephalothin (MIC not indicated) Cephalosporin (drug not specified) 8/10 patients died 1 of 2 patients who survived was also treated with vancomycin [58]

Abbreviations: AST, antimicrobial susceptibility testing; DD, disk diffusion; MIC, minimum inhibitory concentration; MRSA, methicillin-resistant Staphylococcus aureus; MSSA, methicillin-susceptible Staphylococcus aureus.