From the Guidelines
The use of molecular microbiology techniques such as next generation sequencing (NGS) for diagnosing discitis and vertebral osteomyelitis is not recommended for routine clinical use due to unclear significance of positive results, absence of demonstrated impact on antibiotic treatment, high costs, and limited availability. However, these advanced techniques are increasingly being used to identify causative pathogens when conventional culture methods fail. NGS has shown promise in detecting bacterial DNA in tissue samples and has demonstrated higher sensitivity compared to traditional cultures, particularly in patients who have received prior antibiotic therapy 1. The technology can identify multiple organisms simultaneously and detect fastidious or slow-growing bacteria that might be missed by conventional methods.
Key Considerations
- The 2024 guidelines on the diagnosis and treatment of diabetes-related foot infections suggest that molecular microbiology techniques, including NGS, can identify more bacteria from tissue samples, including bone, than conventional cultures 1.
- However, these techniques are currently unable to distinguish dead from living bacterial cells, which may lead to the unjustified use of broad-spectrum antibiotics 1.
- The studies that addressed molecular microbiology for either skin and soft-tissue infections or osteomyelitis included relatively few subjects, were at high risk of bias, and did not provide information on the value of the findings for guidance on clinical management 1.
Clinical Implications
- In clinical practice, NGS has been used successfully to identify pathogens in culture-negative vertebral infections, allowing for targeted antibiotic therapy.
- Despite the potential benefits of molecular techniques, clinicians should continue to request conventional cultures of specimens to determine the identity of causative microorganisms and their antibiotic sensitivities 1.
- The use of molecular microbiology techniques should be reserved for difficult-to-diagnose cases where conventional methods have failed to identify a causative organism.
From the Research
Diagnosis of Discitis or Vertebral Osteomyelitis
- The diagnosis of discitis or vertebral osteomyelitis is often delayed due to non-specific early symptoms and the rarity of the disease 2.
- Magnetic Resonance Imaging (MRI) is commonly used to confirm diagnosis, with most patients undergoing an MRI scan 2, 3.
- MRI appearances in early vertebral osteomyelitis and discitis may be subtle and non-specific, requiring repeat examinations to show typical features 3.
- Blood tests for infection, blood cultures, and a thorough physical examination are also recommended for diagnosis 2, 4.
Role of Molecular Microbiology Techniques
- There is no direct evidence in the provided studies on the use of molecular microbiology techniques such as next-generation sequencing for the diagnosis of discitis or vertebral osteomyelitis.
- However, studies emphasize the importance of identifying the causative microorganism for targeted antibiotic treatment 2, 5, 4.
- Blood cultures and biopsy results are crucial for diagnosing and guiding treatment 2, 5, 6.
Treatment and Management
- Antibiotic therapy is the primary treatment option, with the duration of treatment typically lasting at least 6 weeks 2, 5, 4.
- Surgical debridement and stabilization may be necessary in cases where conservative treatment is ineffective or infection progresses 2, 4.
- A multidisciplinary approach is advocated for the management of vertebral osteomyelitis 2.