Effect of Selected Anti-Staphylococcus aureus Antibiotics on the Microbial Response in Endotracheal Aspirate Samples and Disease Progression
| Treatment and Response Group . | Number of Patients Exposed for Given Days to Respective Antibiotic Prior to Detection of First Heavy Colonization (colonized/VAT/VAP) . | Total Number per Response Group . | Total, % . | Total per Response Group, % . | Minimum Inhibitory Concentration of Isolates to Respective Antibiotic, µg/mL . | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2 days . | 3 days . | 4 days . | 5 days . | 6 days . | 7 days . | 8 days . | 9 days . | ≥10 days . | |||||
| Vancomycin—MRSA (n = 18) | |||||||||||||
| Nonresponding to antibiotics | 0/1/0 | 1/0/0 | 0/1/0 | 3/0/0 | 2/0/0 | 1/1/1 | 0/1/1 | 1/1/0 | 1/0/1 | 9/5/3 | 50.0/27.8/16.7 | 94.4 | 1.00 (0.75; 1.00) |
| Responding to single antibiotic | 0/0/1 | 0/0/1 | 0.0/0.0/5.6 | 5.6 | 1.00 (1.00) | ||||||||
| Responding to antibiotic combination | |||||||||||||
| Linezolid—MRSA (n = 3) | |||||||||||||
| Nonresponding to antibiotics | 0/0/1 | 0/0/1 | 1/0/0 | 1/0/2 | 33.3/0.0/66.7 | 100.0 | 0.75 (0.50; 0.75) | ||||||
| Responding to single antibiotic | |||||||||||||
| Responding to antibiotic combination | |||||||||||||
| Vancomycin—MSSA (n = 15) | |||||||||||||
| Nonresponding to antibiotics | 0/0/1 | 0/0/1 | 0/1/1 | 0/0/1 | 0/2/0 | 0/0/2 | 0/3/6 | 0.0/20.0/40.0 | 60.0 | 1.00 (0.75; 1.00) | |||
| Responding to single antibiotic | |||||||||||||
| Responding to antibiotic combination | 0/1/0 | 1/1/0 | 0/0/1 | 0/1/1 | 1/3/2 | 6.7/20.0/13.3 | 40.0 | 1.00 (0.75; 1.00) | |||||
| Oxacillin—MSSA (n = 9) | |||||||||||||
| Nonresponding to antibiotics | 0/0/1 | 0/0/1 | 0/0/2 | 0.0/0.0/22.2 | 22.2 | 0.38 (0.13; 0.75) | |||||||
| Responding to single antibiotic | 0/0/1 | 0/0/1 | 0.0/0.0/11.1 | 11.1 | 0.50 (0.50) | ||||||||
| Responding to antibiotic combination | 0/1/2 | 0/1/0 | 0/0/1 | 0/0/1 | 0/2/4 | 0.0/22.2/44.4 | 66.7 | 0.75 (0.25; 1.00) | |||||
| Treatment and Response Group . | Number of Patients Exposed for Given Days to Respective Antibiotic Prior to Detection of First Heavy Colonization (colonized/VAT/VAP) . | Total Number per Response Group . | Total, % . | Total per Response Group, % . | Minimum Inhibitory Concentration of Isolates to Respective Antibiotic, µg/mL . | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2 days . | 3 days . | 4 days . | 5 days . | 6 days . | 7 days . | 8 days . | 9 days . | ≥10 days . | |||||
| Vancomycin—MRSA (n = 18) | |||||||||||||
| Nonresponding to antibiotics | 0/1/0 | 1/0/0 | 0/1/0 | 3/0/0 | 2/0/0 | 1/1/1 | 0/1/1 | 1/1/0 | 1/0/1 | 9/5/3 | 50.0/27.8/16.7 | 94.4 | 1.00 (0.75; 1.00) |
| Responding to single antibiotic | 0/0/1 | 0/0/1 | 0.0/0.0/5.6 | 5.6 | 1.00 (1.00) | ||||||||
| Responding to antibiotic combination | |||||||||||||
| Linezolid—MRSA (n = 3) | |||||||||||||
| Nonresponding to antibiotics | 0/0/1 | 0/0/1 | 1/0/0 | 1/0/2 | 33.3/0.0/66.7 | 100.0 | 0.75 (0.50; 0.75) | ||||||
| Responding to single antibiotic | |||||||||||||
| Responding to antibiotic combination | |||||||||||||
| Vancomycin—MSSA (n = 15) | |||||||||||||
| Nonresponding to antibiotics | 0/0/1 | 0/0/1 | 0/1/1 | 0/0/1 | 0/2/0 | 0/0/2 | 0/3/6 | 0.0/20.0/40.0 | 60.0 | 1.00 (0.75; 1.00) | |||
| Responding to single antibiotic | |||||||||||||
| Responding to antibiotic combination | 0/1/0 | 1/1/0 | 0/0/1 | 0/1/1 | 1/3/2 | 6.7/20.0/13.3 | 40.0 | 1.00 (0.75; 1.00) | |||||
| Oxacillin—MSSA (n = 9) | |||||||||||||
| Nonresponding to antibiotics | 0/0/1 | 0/0/1 | 0/0/2 | 0.0/0.0/22.2 | 22.2 | 0.38 (0.13; 0.75) | |||||||
| Responding to single antibiotic | 0/0/1 | 0/0/1 | 0.0/0.0/11.1 | 11.1 | 0.50 (0.50) | ||||||||
| Responding to antibiotic combination | 0/1/2 | 0/1/0 | 0/0/1 | 0/0/1 | 0/2/4 | 0.0/22.2/44.4 | 66.7 | 0.75 (0.25; 1.00) | |||||
Total patient numbers (n) per treatment group are indicated per cohort stratified for the interval of antibiotic treatment and disease phenotype (colonized/VAT/VAP). Response group: level of reduction in Staphylococcus aureus numbers based on semiquantitative endotracheal aspirate analysis (from heavy to light colonization or no S. aureus recovered) by respective antibiotic per treatment group. VAT and/or VAP were diagnosed as previously described [4]. Minimum inhibitory concentration of S. aureus isolates to respective antibiotic per response group showing the median (lower; upper).
Abbreviations: MRSA, methicillin-resistant Staphylococcus aureus; MSSA, methicillin-susceptible Staphylococcus aureus; VAP, ventilator-associated pneumonia; VAT, ventilator-associated tracheobronchitis.
Effect of Selected Anti-Staphylococcus aureus Antibiotics on the Microbial Response in Endotracheal Aspirate Samples and Disease Progression
| Treatment and Response Group . | Number of Patients Exposed for Given Days to Respective Antibiotic Prior to Detection of First Heavy Colonization (colonized/VAT/VAP) . | Total Number per Response Group . | Total, % . | Total per Response Group, % . | Minimum Inhibitory Concentration of Isolates to Respective Antibiotic, µg/mL . | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2 days . | 3 days . | 4 days . | 5 days . | 6 days . | 7 days . | 8 days . | 9 days . | ≥10 days . | |||||
| Vancomycin—MRSA (n = 18) | |||||||||||||
| Nonresponding to antibiotics | 0/1/0 | 1/0/0 | 0/1/0 | 3/0/0 | 2/0/0 | 1/1/1 | 0/1/1 | 1/1/0 | 1/0/1 | 9/5/3 | 50.0/27.8/16.7 | 94.4 | 1.00 (0.75; 1.00) |
| Responding to single antibiotic | 0/0/1 | 0/0/1 | 0.0/0.0/5.6 | 5.6 | 1.00 (1.00) | ||||||||
| Responding to antibiotic combination | |||||||||||||
| Linezolid—MRSA (n = 3) | |||||||||||||
| Nonresponding to antibiotics | 0/0/1 | 0/0/1 | 1/0/0 | 1/0/2 | 33.3/0.0/66.7 | 100.0 | 0.75 (0.50; 0.75) | ||||||
| Responding to single antibiotic | |||||||||||||
| Responding to antibiotic combination | |||||||||||||
| Vancomycin—MSSA (n = 15) | |||||||||||||
| Nonresponding to antibiotics | 0/0/1 | 0/0/1 | 0/1/1 | 0/0/1 | 0/2/0 | 0/0/2 | 0/3/6 | 0.0/20.0/40.0 | 60.0 | 1.00 (0.75; 1.00) | |||
| Responding to single antibiotic | |||||||||||||
| Responding to antibiotic combination | 0/1/0 | 1/1/0 | 0/0/1 | 0/1/1 | 1/3/2 | 6.7/20.0/13.3 | 40.0 | 1.00 (0.75; 1.00) | |||||
| Oxacillin—MSSA (n = 9) | |||||||||||||
| Nonresponding to antibiotics | 0/0/1 | 0/0/1 | 0/0/2 | 0.0/0.0/22.2 | 22.2 | 0.38 (0.13; 0.75) | |||||||
| Responding to single antibiotic | 0/0/1 | 0/0/1 | 0.0/0.0/11.1 | 11.1 | 0.50 (0.50) | ||||||||
| Responding to antibiotic combination | 0/1/2 | 0/1/0 | 0/0/1 | 0/0/1 | 0/2/4 | 0.0/22.2/44.4 | 66.7 | 0.75 (0.25; 1.00) | |||||
| Treatment and Response Group . | Number of Patients Exposed for Given Days to Respective Antibiotic Prior to Detection of First Heavy Colonization (colonized/VAT/VAP) . | Total Number per Response Group . | Total, % . | Total per Response Group, % . | Minimum Inhibitory Concentration of Isolates to Respective Antibiotic, µg/mL . | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2 days . | 3 days . | 4 days . | 5 days . | 6 days . | 7 days . | 8 days . | 9 days . | ≥10 days . | |||||
| Vancomycin—MRSA (n = 18) | |||||||||||||
| Nonresponding to antibiotics | 0/1/0 | 1/0/0 | 0/1/0 | 3/0/0 | 2/0/0 | 1/1/1 | 0/1/1 | 1/1/0 | 1/0/1 | 9/5/3 | 50.0/27.8/16.7 | 94.4 | 1.00 (0.75; 1.00) |
| Responding to single antibiotic | 0/0/1 | 0/0/1 | 0.0/0.0/5.6 | 5.6 | 1.00 (1.00) | ||||||||
| Responding to antibiotic combination | |||||||||||||
| Linezolid—MRSA (n = 3) | |||||||||||||
| Nonresponding to antibiotics | 0/0/1 | 0/0/1 | 1/0/0 | 1/0/2 | 33.3/0.0/66.7 | 100.0 | 0.75 (0.50; 0.75) | ||||||
| Responding to single antibiotic | |||||||||||||
| Responding to antibiotic combination | |||||||||||||
| Vancomycin—MSSA (n = 15) | |||||||||||||
| Nonresponding to antibiotics | 0/0/1 | 0/0/1 | 0/1/1 | 0/0/1 | 0/2/0 | 0/0/2 | 0/3/6 | 0.0/20.0/40.0 | 60.0 | 1.00 (0.75; 1.00) | |||
| Responding to single antibiotic | |||||||||||||
| Responding to antibiotic combination | 0/1/0 | 1/1/0 | 0/0/1 | 0/1/1 | 1/3/2 | 6.7/20.0/13.3 | 40.0 | 1.00 (0.75; 1.00) | |||||
| Oxacillin—MSSA (n = 9) | |||||||||||||
| Nonresponding to antibiotics | 0/0/1 | 0/0/1 | 0/0/2 | 0.0/0.0/22.2 | 22.2 | 0.38 (0.13; 0.75) | |||||||
| Responding to single antibiotic | 0/0/1 | 0/0/1 | 0.0/0.0/11.1 | 11.1 | 0.50 (0.50) | ||||||||
| Responding to antibiotic combination | 0/1/2 | 0/1/0 | 0/0/1 | 0/0/1 | 0/2/4 | 0.0/22.2/44.4 | 66.7 | 0.75 (0.25; 1.00) | |||||
Total patient numbers (n) per treatment group are indicated per cohort stratified for the interval of antibiotic treatment and disease phenotype (colonized/VAT/VAP). Response group: level of reduction in Staphylococcus aureus numbers based on semiquantitative endotracheal aspirate analysis (from heavy to light colonization or no S. aureus recovered) by respective antibiotic per treatment group. VAT and/or VAP were diagnosed as previously described [4]. Minimum inhibitory concentration of S. aureus isolates to respective antibiotic per response group showing the median (lower; upper).
Abbreviations: MRSA, methicillin-resistant Staphylococcus aureus; MSSA, methicillin-susceptible Staphylococcus aureus; VAP, ventilator-associated pneumonia; VAT, ventilator-associated tracheobronchitis.
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