Microbiological diagnosis of suspected vertebral osteomyelitis with a focus on the yield of percutaneous needle biopsy: a 10-year cohort study

The Biopsy Site is Critical for Bacterial Culture After Percutaneous Biopsy in Patients with Pyogenic Spondylodiscitis

BACKGROUND

Previous studies have found that the positive rate of bacterial culture after percutaneous needle biopsy in patients with suspected pyogenic spondylodiscitis is influenced by a number of factors. At the same time, the choice of puncture site in percutaneous biopsy has been controversial. The objective of this study is to explore the factors influencing the positive rate of bacterial culture after percutaneous biopsy in patients with pyogenic spondylodiscitis.

METHODS

The medical records of 186 patients with suspected spinal infection who underwent C-type arm-guided percutaneous biopsy in Beijing Chest Hospital Affiliated to Capital Medical University from January 2023 to December 2023 were retrospectively analyzed. According to inclusion and exclusion criteria, a total of 116 patients with suspected pyogenic spondylodiscitis were included. The positive rate of bacterial culture was calculated, and the effects of age, gender, course of disease, preoperative fever, preoperative antibiotic use, preoperative white blood cell count, C-reactive protein (CRP), erythrocyte sedimentation rate, and puncture site on the positive rate of culture were discussed. Logistic regression analysis was used to identify the relevant factors affecting the positive rate of culture.

RESULTS

Among the 116 patients, 63 were males and 53 were females. Age ranged from 13 to 87 years, with a median age of 59.5 years. The results of bacterial culture in 42 patients were positive, with a positive rate of 36.2% (42/116), including Staphylococcus aureus in 12 cases, streptococcus in 5 cases, Brucella in 5 cases, Escherichia coli in 4 cases, Staphylococcus epidermidis in 3 cases, Pseudomonas aeruginosa in 2 cases, Enterococcus faecalis in 2 cases, anaerobic bacteria in 2 cases, and other bacteria in 7 cases. The positive rate of bacterial culture was 22.6% (14/62) in patients with vertebral body puncture and 51.9% (28/54) in patients with intervertebral disc puncture, and there was a significant difference between the 2 groups (P = 0.001). Logistic regression analysis showed that the course of disease, the increase of CRP before puncture, and the site of puncture were the factors influencing the positive rate of culture.

CONCLUSIONS

The course of disease, the elevation of CRP before puncture, and the site of puncture were the factors influencing the positive rate of bacterial culture in percutaneous biopsy of pyogenic spondylodiscitis patients. The positive rate of obtaining intervertebral disc in percutaneous puncture was significantly higher than that of vertebral body, suggesting that intervertebral disc is a more critical puncture site.

Culture-Negative Native Vertebral Osteomyelitis: A Narrative Review of an Underdescribed Condition

The incidence of culture-negative NVO (CN-NVO) cases is increasing, presenting significant diagnostic and therapeutic challenges due to the inability to isolate causative organisms with conventional microbiological methods. Factors influencing the diagnosis of CN-NVO include prior antimicrobial therapy, low pathogen burden, fastidious or intracellular organisms, technical issues, and non-infectious mimickers. Diagnosis often relies on imaging modalities like magnetic resonance imaging (MRI) and computed tomography (CT)-guided biopsy, though these methods can sometimes fail to yield positive microbiological results. Advanced diagnostic tools, such as polymerase chain reaction (PCR), metagenomic next-generation sequencing (mNGS), and cell-free DNA analysis, may be necessary to identify the pathogen. The causative pathogen cannot be isolated in some patients, among which an empirical antimicrobial therapy should be initiated. This narrative review discusses the management, monitoring, surgical indications, and outcomes for patients with CN-NVO.

Pathogen detection in suspected spinal infection: metagenomic next-generation sequencing versus culture

PURPOSE

The aim is to compare the pathogen detection performance of metagenomic next-generation sequencing (mNGS) and the culturing of percutaneous needle biopsy samples obtained from an individual with a suspected spinal infection.

METHODS

A retrospective study of 141 individuals with a suspected spinal infection was conducted, and mNGS was performed. The microbial spectra and detection performance between mNGS and the culturing-based method were compared, and the effects of antibiotic intervention and biopsy on the detection performance were assessed.

RESULTS

The microorganisms isolated most commonly via the culturing-based method were Mycobacterium tuberculosis (n = 21), followed by Staphylococcus epidermidis (n = 13). The most common microorganisms detected via mNGS were Mycobacterium tuberculosis complex (MTBC) (n = 39), followed by Staphylococcus aureus (n = 15). The difference in the type of detected microorganisms between culturing and mNGS was observed only in Mycobacterium (P = 0.001). mNGS helped identify potential pathogens in 80.9% of cases, which was significantly higher than the positivity rate of 59.6% observed for the culturing-based method (P < 0.001). Moreover, mNGS had a sensitivity of 85.7% (95% CI, 78.4% to 91.3%), a specificity of 86.7% (95% CI, 59.5% to 98.3%), and sensitivity gains of 35% (85.7% vs. 50.8%; P < 0.001) during culturing, while no differences were observed in the specificity (86.7% vs. 93.3%; P = 0.543). In addition, antibiotic interventions significantly lowered the positivity rate of the culturing-based method (66.0% vs. 45.5%, P = 0.021) but had no effects on the results of mNGS (82.5% vs. 77.3%, P = 0.467).

CONCLUSION

The use of mNGS could result in a higher detection rate compared to that observed with the culturing-based method in an individual with spinal infection and is particularly valuable for evaluating the effects of a mycobacterial infection or previous antibiotic intervention.

Is There a Difference in Clinical Features, Microbiological Epidemiology and Effective Empiric Antimicrobial Therapy Comparing Healthcare-Associated and Community-Acquired Vertebral Osteomyelitis?

Background: Empiric antibiotic therapy for suspected vertebral osteomyelitis (VO) should be initiated immediately in severely ill patients, and might be necessary for culture-negative VO. The current study aimed to identify differences between community-acquired (CA) and healthcare-associated (HA) VO in terms of clinical presentation, causative pathogens, and antibiotic susceptibility. Methods: Cases of adult patients with VO treated at a German university orthopaedic trauma center between 2000 and 2020 were retrospectively reviewed. Patient history was used to distinguish between CA and HA VO. Susceptibility of antibiotic regimens was assessed based on antibiograms of the isolated pathogens. Results: A total of 155 patients (with a male to female ratio of 1.3; and a mean age of 66.1 ± 12.4 years) with VO were identified. In 74 (47.7%) patients, infections were deemed healthcare-associated. The most frequently identified pathogens were Staphylococcus aureus (HAVO: 51.2%; CAVO: 46.8%), and Coagulase-negative Staphylococci (CoNS, HAVO: 31.7%; CAVO: 21.3%). Antibiograms of 45 patients (HAVO: n = 22; CAVO: n = 23) were evaluated. Significantly more methicillin-resistant isolates, mainly CoNS, were found in the HAVO cohort (27.3%). The highest rate of resistance was found for cefazolin (HAVO: 45.5%; CAVO: 26.1%). Significantly higher rates of resistances were seen in the HAVO cohort for mono-therapies with meropenem (36.4%), piperacillin–tazobactam (31.8%), ceftriaxone (27.3%), and co-amoxiclav (31.8%). The broadest antimicrobial coverage was achieved with either a combination of piperacillin–tazobactam + vancomycin (CAVO: 100.0%; HAVO: 90.9%) or meropenem + vancomycin (CAVO: 100.0%; HAVO: 95.5%). Conclusion: Healthcare association is common in VO. The susceptibility pattern of underlying pathogens differs from CAVO. When choosing an empiric antibiotic, combination therapy must be considered.

Large increase of vertebral osteomyelitis in France: a 2010-2019 cross-sectional study

Vertebral osteomyelitis (VO) represents 4-10% of bone and joint infections. In Western countries, its incidence seems to increase, simultaneously with an increasing number of comorbidities among an ageing population. This study aimed to assess the evolution of VO epidemiology in France over the 2010-2019 decade. A nationwide cross-sectional study was conducted using the French hospital discharge data collected through the French diagnosis-related groups 'Programme de Médicalisation des Systèmes d'Information'. VOs were detected with a previously validated case definition using International Classification of Diseases 10 (ICD-10) codes, implemented with the French current procedural terminology codes. The study population included all patients hospitalised in France during the 2010-2019 decade, aged 15 years old and more. Patient and hospital stay characteristics and their evolutions were described. During the study period, 42 105 patients were hospitalised for VO in France involving 60 878 hospital stays. The mean VO incidence was 7.8/100 000 over the study period, increasing from 6.1/100 000 in 2010 to 11.3/100 000 in 2019. The mean age was 64.8 years old and the sex ratio was 1.56. There were 31 341 (74.4%) patients with at least one comorbidity and 3059 (7.3%) deceased during their hospital stay. Even if rare, device-associated VOs (4450 hospital stays, 7.3%) highly increased over the period. The reliability of the method, based upon an exhaustive database and a validated case definition, provided an effective tool to compare data over time in real-life conditions to regularly update the epidemiology of VO.