Introduction
Material and methods
Study design
Study population
Multiplex PCR evaluation
Routine cultivation of synovial fluid
Diagnostic tests
Statistical analysis
Results
Demographics and infection classification
Performance of the multiplex PCR system
Positive % agreement | Negative % agreement | Overall % agreement | Kappa | |
---|---|---|---|---|
Total | 75.0 (57.6–86.9) | 91.4 (80.8–96.6) | 85.6 (78.3–92.8) | 0.68 (0.52–0.84) |
TKA | 73.7 (50.8–99.4) | 93.8 (78.6–99.2) | 86.3 (76.8–95.7) | 0.70 (0.49–0.91) |
THA | 72.7 (42.8–90.5) | 86.4 (65.6–95.9) | 81.8 (68.7–95.0) | 0.59 (0.29–0.89) |
Isolated microorganism | mPCR (n = 29) | SF culture (n = 32) |
---|---|---|
Staphylococcus aureus
| 13 | 18 |
Coagulase-negative Staphylococci | 7 | 5 |
Cutibacterium avidum/granulosum | 2 | 1 |
Cutibacterium acnes
| 3 | 0 |
Pseudomonas aeruginosa
| 2 | 2 |
Streptococcus spp. | 2 | 2 |
Escherichia coli
| 1 | 1 |
Enterococcus faecalis
| 1 | 1 |
Klebsiella pneumoniae
| 1 | 0 |
Proteus spp. | 1 | 1 |
Finegoldia magna
| 1 | 1 |
Enterobacter cloacae complex | 0 | 1 |
Actinomyces neuii
| 0 | 1 |
Total | 34 | 34 |
mPCR | Conventional culture SF | Combination | |
---|---|---|---|
Sensitivity | 71.1% (55.1–83.0) | 84.2% (69.1–92.8) | 92.1% (78.3–97.9) |
Specificity | 96.2% (86.1–99.6) | 100.0% (91.6–100) | 96.2% (86.1–99.6) |
LR+ | 18.47 (4.68–72.99) | – | 23.95 (6.13–93.51) |
LR− | 0.30 (0.18–0.50) | 0.16 (0.08–0.33) | 0.08 (0.03–0.24) |
AUC | 0.84 (0.76–0.91) | 0.92 (0.86–0.98) | 0.94 (0.89–0.99) |
PPV | 93.1% (83.9–100) | 100% (100) | 94.6% (87.3–100) |
NPV | 82.0% (72.3–91.6) | 89.7% (81.8–97.5) | 94.3% (88.1–100) |
Performance of resistance detection
Concordant microorganisms | mPCR gene resistance marker | Culture-resistance |
---|---|---|
Enterococcus faecalis
| Macrolides/lincosamides [ermC] | No resistance |
Coagulase-negative Staphylococci | Aminoglycosides aac(6′)/aph(2″) | Gentamicin |
Macrolides/lincosamides [ermA] | Oxacillin | |
Ciprofloxacin | ||
Staphylococcus aureus
| No resistance | No resistance |
Coagulase-negative Staphylococci | No resistance | No resistance |
Cutibacterium avidum/granulosum | No resistance | Clindamycin |
Escherichia coli
| Fluoroquinolones [gyrA] | No resistance |
Pseudomonas aeruginosa
| No resistance | No resistance |
Staphylococcus aureus
| No resistance | No resistance |
Staphylococcus aureus
| Macrolides/lincosamides [ermA] | Erythromycin, clindamycin |
Glycopeptide [vanB] | ||
Staphylococcus aureus
| No resistance | No resistance |
Staphylococcus aureus
| Macrolides/lincosamides [ermA] | Erythromycin, clindamycin |
Staphylococcus aureus
| Rifampicin [rpoB] | Fosfomycin |
Staphylococcus aureus
| Macrolides/lincosamides [ermC] | Erythromycin, clindamycin |
Pseudomonas aeruginosa
| No resistance | Ciprofloxacin |
Staphylococcus aureus
| No resistance | Erythromycin, clindamycin |
Staphylococcus aureus
| No resistance | Erythromycin, clindamycin |
Proteus spp. | No resistance | No resistance |
Staphylococcus aureus
| No resistance | No resistance |
Staphylococcus aureus
| No resistance | No resistance |
Staphylococcus aureus
| Macrolides/lincosamides [ermC] | Erythromycin, clindamycin |
Aminoglycosides aac(6′)/aph(2″) | ||
Staphylococcus aureus
| No resistance | Erythromycin, clindamycin |
Streptococcus spp. | No resistance | No resistance |
Streptococcus spp. | No resistance | Erythromycin, clindamycin |
Doxycyclin |
Discussion
Present study | Morgenstern et al. [7] | Renz et al. [6] | Achermann et al. [2] | Portillo et al. [5] | Hischebeth et al. [4] | Borde et al. [3] | Suda et al. [8] | |
---|---|---|---|---|---|---|---|---|
Test material | ||||||||
mPCR | Synovial fluid | Synovial fluid | Sonication fluid | Sonication fluid | Sonication fluid | “Pooled PCR” | Tissue samples | Tissue samples |
Culture | Synovial fluid | Synovial fluid | Sonication fluid | Sonication fluid | sonication + tissue | Sonication fluid | Tissue samples | Tissue samples |
Used criteria | MSIS/EBJIS | EBJIS | EBJIS | Modified EBJIS | Modified EBJIS | MSIS | nm | MSIS |
Overall % agreement | 86% | 82% | 64% | 57% | nm | nm | 82% | nm |
Sensitivity mPCR | 71%/52% | 60% | 51% | 78% | 96% | 67% | nm | 31% |
Sensitivity culture | ||||||||
Synovial | 84%/57% | 52% | nm | nm | nm | nm | nm | nm |
Sonication | 86%/66% | 61% | 58% | 62% | 71% | 89% | nm | nm |
Tissue | 74%/60% | 45% | 51% | nm | 67% | 67% | nm | 85% |
Specificity mPCR | 90%/100% | 89% | 94% | nm | 100% | 100% | nm | 100% |
Specificity culture | ||||||||
Synovial | 100%/100% | 98% | nm | nm | nm | nm | nm | nm |
Sonication | 100%/100% | 91% | 100% | nm | 100% | 62% | nm | nm |
Tissue | 95%/100% | 96% | 100% | nm | 98% | 82% | nm | 100% |