Table 1: Comparison of Healthcare Associated and Community Associated MRSA
|
Characteristic |
Healthcare Associated-MRSA (HA-MRSA) |
Community Associated-MRSA (CA-MRSA) |
|
First Identified |
1961 |
1981 |
|
Antimicrobial Resistance |
Multidrug |
Only Beta-Lactams |
|
Clinical Manifestations |
More invasive (e.g., pneumonia, bloodstream infections) |
Less invasive (e.g., skin and soft tissue infections) |
|
Age of Patients |
Older |
Younger |
|
|
|
|
|
Molecular Typing Methods |
|
|
|
Pulse-field Gel Electrophoresis (PFGE) |
USA 100*, USA200, USA800 |
USA 300*, USA 400 |
|
SCCmec type |
II* I, III, IV |
IV*, V, VI |
|
Spa type |
t002*, t018 |
t008*, t128 |
|
Multi-locus sequence typing (MLST) |
ST35*, ST36 |
ST8*, ST1 |
|
Clonal Complex |
CC5*, CC30 |
CC8*, CC1 |
Table 2: In vitro Activity of Antimicrobial Agents Against Staphylococcus aureus
|
|
MIC against MSSA (μg/mL) |
MIC against MRSA (μg/mL) |
||||
|
Antibiotic |
Range |
50% |
90% |
Range |
50% |
90% |
|
Penicillins |
|
|
|
|
|
|
|
Penicillin |
<0.06-128 |
16 |
128 |
32-128 |
64 |
128 |
|
Ampicillin |
2.0->32 |
>32 |
>32 |
4.0>32 |
>32 |
>32 |
|
Oxacillin |
0.25-2.0 |
0.5 |
1 |
16.0->128 |
>64 |
>128 |
|
Nafcillin |
0.25-1 |
0.5 |
1 |
-- |
-- |
-- |
|
Methicillin |
0.5-4 |
1 |
4 |
8->128 |
64 |
>64 |
|
Dicloxacillin |
0.06-0.5 |
0.25 |
0.5 |
-- |
-- |
-- |
|
Cephalosporins |
|
|
|
|
|
|
|
Cephalothin |
0.125-0.5 |
0.5 |
0.5 |
4.0->32 |
>32 |
>32 |
|
Cefazolin |
0.5-4 |
1 |
2 |
-- |
-- |
-- |
|
Cephalexin |
4-16 |
8 |
16 |
128-256 |
>128 |
256 |
|
Cefaclor |
1-32 |
4 |
16 |
>64->128 |
128 |
>128 |
|
Cefuroxime |
0.5-2 |
1 |
2 |
64->128 |
>128 |
>128 |
|
Cefotaxime |
0.5->16.0 |
>16 |
>16 |
2.0->32 |
>32 |
>32 |
|
Cefepime |
1-8 |
4 |
4 |
8->64 |
64 |
>64 |
|
Ceftazidime |
4-16 |
8 |
16 |
16->64 |
64 |
>64 |
|
Ceftriaxone |
2-4 |
4 |
4 |
16->64 |
>64 |
>64 |
|
Cefoperazone |
2-4 |
2 |
4 |
32->256 |
>256 |
>256 |
|
Cefixime |
8-64 |
16 |
32 |
>32->64 |
>32 |
>64 |
|
Cefdinir |
0.125-1 |
0.25 |
1 |
0.5->64 |
64 |
>64 |
|
Cefpodoxime |
2-8 |
4 |
8 |
>64->128 |
>64 |
>128 |
|
Flomoxef |
0.12-4 |
0.5 |
4 |
8->32 |
>32 |
>32 |
|
Moxalactam |
2-16 |
8 |
16 |
>32 |
>32 |
>32 |
|
Cefpirome |
0.50-2 |
1 |
2 |
32-128 |
128 |
128 |
|
ß-lactam/ß-lactam inhibitors |
|
|
|
|
|
|
|
Amoxicillin/clavulanate |
0.12-2 |
1 |
2 |
16-64 |
32 |
64 |
|
Ampicillin/sulbactam |
0.06-2 |
1 |
2 |
8-32 |
32 |
32 |
|
Piperacillin-tazobactam |
0.06-32 |
1 |
1 |
-- |
-- |
-- |
|
Carbapenems |
|
|
|
|
|
|
|
Meropenem |
0.06-1 |
0.12 |
0.12 |
0.5-16 |
8 |
>8 |
|
Imipenem |
0.12-0.5 |
0.12 |
0.25 |
0.05->16.0 |
4 |
16 |
|
Glycopeptides |
|
|
|
|
|
|
|
Vancomycin |
0.25-2 |
1 |
2.0 |
0.24-4.0 |
2 |
2.0 |
|
Teicoplanin |
0.25-4.0 |
0.5 |
0.5 |
0.5-4.0 |
0.5 |
1.0 |
|
Oritavancin |
0.12-0.5 |
0.25 |
0.25 |
0.12-1.0 |
0.25 |
0.5 |
|
Macrolides |
|
|
|
|
|
|
|
Erythromycin |
0.13-4 |
0.25 |
4 |
0.06->32 |
>32 |
>32 |
|
Azithromycin |
0.25-8 |
1 |
4 |
>128 |
>128 |
>128 |
|
Clarithromycin |
0.13-4 |
0.25 |
1 |
0.125->64 |
>64 |
>64 |
|
Dirithromycin |
0.25-8 |
0.5 |
4 |
>64 |
>64 |
>64 |
|
Roxithromycin |
0.13-0.16 |
0.5 |
4 |
>64 |
>64 |
>64 |
|
Lincosamides, Streptogramins and Ketolides |
||||||
|
Clindamycin |
<0.06-0.125 |
0.125 |
0.125 |
>256 |
>256 |
>256 |
|
Quinuprisitin-Dalfopristin |
0.25 |
0.5 |
0.25-1 |
0.5 |
1 |
0.25-1 |
|
Telithromycin |
0.015-32 |
0.06 |
0.25 |
0.03->128 |
0.25 |
0.5 |
|
Aminoglycosides |
|
|
|
|
|
|
|
Gentamicin |
0.06-16 |
0.12 |
0.5 |
0.06-64 |
1 |
32 |
|
Tobramycin |
0.06-32 |
0.125 |
0.25 |
-- |
-- |
-- |
|
Amikacin |
0.5-4 |
1 |
2 |
2-64 |
16 |
32 |
|
Quinolones |
|
|
|
|
|
|
|
Ofloxacin |
0.12-1 |
0.5 |
1 |
0.25-32 |
8.0 |
16 |
|
Pefloxacin |
0.12-2 |
0.5 |
1 |
0.25-128 |
32 |
128 |
|
Rufloxacin |
1.0-16 |
1.0 |
4.0 |
1.0->32 |
1.0 |
4.0 |
|
Sparfloxacin |
<0.015-0.12 |
0.03 |
0.12 |
<0.015-16 |
4 |
16 |
|
Ciprofloxacin |
0.03-4.0 |
0.5 |
1.0 |
0.25->128 |
32 |
64 |
|
Norfloxacin |
0.25-1.0 |
0.5 |
1.0 |
0.25->32 |
0.5 |
1.0 |
|
Levofloxacin |
0.06-0.25 |
0.13 |
0.25 |
0.25-32 |
0.5 |
16 |
|
Moxifloxacin |
0.016-0.13 |
0.03 |
0.06 |
0.016-8 |
0.06 |
4 |
|
Gatifloxacin |
0.03-0.25 |
0.06 |
0.13 |
0.03-16 |
0.13 |
16 |
|
Trovafloxacin |
0.008-0.013 |
0.03 |
0.06 |
0.016-8 |
0.013 |
4 |
|
Clinafloxacin |
0.008-0.06 |
0.03 |
0.06 |
0.03-16 |
0.06 |
8 |
|
Gemifloxacin |
0.008-16 |
0.016 |
0.03 |
0.016-16 |
2 |
8 |
|
Sitafloxacin |
0.008-4 |
0.015 |
0.03 |
0.015-8 |
0.25 |
0.5 |
|
Miscellaneous |
|
|
|
|
|
|
|
Tetracycline |
0.006-124 |
0.25 |
64 |
-- |
-- |
-- |
|
Trimethoprim |
0.06-0.25 |
0.125 |
0.25 |
0.25-1 |
0.5 |
1 |
|
Sulfamethoxazole |
1.19-4.75 |
2.38 |
4.75 |
4.75-19 |
9.5 |
19 |
|
Fusidic acid |
0.06-0.12 |
0.06 |
0.06 |
0.03-8 |
0.06 |
0.06 |
|
Rifampin |
<0.03->16 |
<0.03 |
1.0 |
<0.03->16 |
>16 |
>16 |
|
Mupirocin |
0.06-2 |
0.25 |
0.25 |
0.125->256 |
0.25 |
0.5 |
|
Linezolid |
0.5-1 |
1 |
1 |
0.5-1 |
1 |
1 |
|
Daptomycin |
≤0.12-2 |
0.25 |
0.5 |
≤0.12-1 |
0.25 |
0.5 |
|
Tigecycline |
0.25-0.5 |
0.5 |
0.5 |
0.25-1 |
0.5 |
1 |
aMSSA: Methicillin-susceptible S. aureus; MRSA: Methicillin-resistant S. aureus.
Table 3. Suggested Antibiotics, Doses
and Duration for Treatment of Staphylococcus aureus Infections
|
Infection type |
Penicillin allergy status |
Initial IV regimen |