Diagnostic efficiency of metagenomic next-generation sequencing on spinal infection and prognosis.

Objectives: Spinal infection is a rare infectious disease that is difficult to treat. The incidence of spinal infection is on the rise with the experiential use of antibiotics, the increasing incidence of drug-resistant bacteria, and the improvement of detection techniques. Traditional detection methods have limitations such as low sensitivity and long time-consuming in the diagnosis of spinal infection. In the clinical diagnosis and treatment of spinal infection, it has always been the focus and difficulty to determine the type of pathogens and to use antibiotics in a targeted manner. Many patients in the early stage of spinal infection due to the limitations of traditional detection methods cannot be quickly and accurately diagnosed, resulting in diagnosis delay, missed the best treatment time, bringing disastrous consequences to patients. There is an urgent need for a high-specificity, high-sensitivity, and time-saving test technique in clinical practice, which can simultaneously distinguish and identify the pathogen of spinal infection. Metagenomic next-generation sequencing (mNGS) is a new frontier technology emerging in recent years. It can detect all known pathogens in samples and has been used to diagnose clinically atypical and rare infectious diseases. This study aims to analyze the sensitivity of mNGS technique in diagnosing pathogens after spinal infection and its effect on prognosis.

Methods: Clinical data of 82 patients with spinal infection admitted to Xiangya Hospital of Central South University from January 2019 to December 2021 were retrospectively analyzed. Peripheral blood erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and procalcitonin (PCT) were routinely performed before surgery, and focal tissue specimens were obtained during surgery. Microbial culture, histopathological examination, and mNGS detection were performed. All patients were assigned into a targeted medication group (=71) and an experienced treatment group (=1) based on the results of mNGS. After regular follow-up, the sensitivity of mNGS to detect pathogens of spinal infection and its effect on prognosis were evaluated.

Results: The positive rate of mNGS (86.59%, 71/82) was significantly higher than that of microbial culture (18.99%, 15/79) and PCT (30.23%, 13/43). There were no significant differences in preoperative temperature, white blood cell count, neutrophil ratio, and scores of Visual Analogue Scale between the targeted medication group and the experienced treatment group. Preoperative use of antibiotics had no significant effect on the positive rate of mNGS and microbial culture (=0.681). According to the targeted medication group, postoperative CRP and ESR showed a decreasing trend, and the ESR was significantly lower than that of the experienced treatment group at 30 days follow-up (=0.044).

Conclusions: Compared with the microbial culture or PCT, mNGS has a higher sensitivity rate to detect pathogens of spinal infection. Patients receiving targeted antibiotics based on the results of mNGS have better outcomes than those receiving the experienced medicine.