From: Microbiology of diabetic foot infections: from Louis Pasteur to ‘crime scene investigation’
Molecular Method | Potential Advantages | Potential Disadvantages | Time to results | Current cost |
---|---|---|---|---|
Bacterial identification and quantificationa | ||||
PCR and pyrosequencing | Delineates full array bacteria present, including almost all gram-positive, gram-negative and obligate anaerobic species; allows broad-range amplification by PCR; detects even small concentrations of microorganisms; avoids false-negative results related to recent antibiotic therapy; can help differentiate colonization from infection | Identifies only 16S bacteria; fails to detect some bacterial and nonbacterial microorganisms; cannot reliably distinguish between viable and nonviable organisms as it amplifies dormant or dead bacteria; unable to test for phenotypic antibiotic sensitivity | 4 to 24 hours | About US $13/ target region |
q PCR assaya | Measures the quantity of a target sequence; determines the number of DNA copies in a sample; estimates bacterial load; helps differentiate colonization from infection | Quantifies DNA from both viable and nonviable bacteria; requires a well-equipped laboratory with PCR facilities | 2 to 6 hours | About US $10 per sample |
Virulence genes factors for S. aureusb | ||||
PCR assay | Allows virulence genotyping among strains of S. aureus | Only patients with monomicrobial culture for S. aureus were included in published study | 2 to 5 hours | About US $5/assay |
DNA microarray | Carries a set of 334 different probes for genotyping S. aureus isolates; analyzes a large number of samples (96/well strip) | Only patients with monomicrobial culture for S. aureus were included in published study | 4 to ~5 hours | About US $ 60/96-well strip |