Correlation Between Microbial Infection and Lumbar Degenerative Disease Based on High-throughput Gene Sequencing

Modic degeneration of the vertebral endplate in the lumbar spine refers to a common abnormal signal change in the endplate and subendplate bone on lumbar magnetic resonance imaging after excluding tumors and tuberculosis. It reflects the microscopic changes in tissue biochemistry within the endplate and the manifestations of endplate degeneration. Modic and other scholars have conducted detailed research on it and classified it into three types based on the signal level and pathological and biochemical changes on MRI, as shown in Figure 1. Type I (edema type): Low signal on T1WI, high signal on T2WI, and cracks in the endplate can be found in the granulation tissue of new blood vessels in the bone marrow; Type II (fatty type): High signal on T1WI, equal or slightly high signal on T2WI, adjacent bone marrow tissue replaced by adipocytes, and end plate rupture; Type III (sclerotic type): Low signal on T1WI and T2WI, with sclerosis changes in the endplate and subchondral bone.

The Pfirmmann grading system based on sagittal T2WI of lumbar magnetic resonance imaging is a semi quantitative evaluation method for the degree of lumbar disc degeneration, which can display the morphological changes of lumbar disc degeneration. It is currently a widely used and highly recognized grading system for evaluating the degree of lumbar disc degeneration. This grading system was proposed by Pfirmmann in 2001, which evaluates the level of lumbar disc degeneration based on indicators such as signal intensity, disc shape, and intervertebral space changes in the midsagittal position of the T2WI sequence.

Collect blood samples from patients before surgery and intervertebral disc tissue after decompression during surgery. Send blood samples and intervertebral disc tissue samples to bacterial culture analysis for microbial species and drug sensitivity, and conduct smear observation, aerobic and anaerobic environment culture identification. The VitekII Compact fully automated microbial identification and drug sensitivity analysis system (BioMerieux, Marcy Ioile, France) was used for bacterial identification and sensitivity testing of commonly used clinical drugs, and the paper diffusion method (K-B method) was used to increase sensitivity testing of commonly used antibiotics such as levofloxacin, polymyxin B, cefoperazone/sulbactam, minocycline, and vancomycin.

Collect blood samples from patients before surgery, and collect intervertebral disc tissue from patients after decompression during surgery using sterile collection tubes. To ensure the comprehensive identification of microbial species, this study plans to simultaneously sequence RNA and DNA using the TIAAmp MicroRNA and DNA Extraction Kit (Beijing Tiangen Biochemical Technology Co., Ltd., China), and extract RNA and DNA from blood samples and intervertebral disc tissue samples according to the instructions in the manual.

For microbial data analysis, use the Sanger method to map the sequencing results in BWA; Convert data to bam format using SAMtools; After using the built-in script of the software for filtering, use IGV software to process the mapping data; Assemble consistent sequences using SAMTools and BCFtools; Visualize using IGV software; Verify the sequencing accuracy of Nanopore MinION by comparing consistent sequences and Sanger method reference sequences.

The visual analog scale (VAS) is used for pain assessment. It is widely used in clinical practice in China, and the basic method is to use a vernier ruler with a length of about 10cm, marked with 10 scales on one side, with both ends marked as "0" and "10" respectively. A score of 0 indicates painlessness, and a score of 10 represents the most severe pain that cannot be tolerated.

The Japanese Orthopaedic Association Scores (JOA) is a neurological function scoring system recommended by the Japanese Orthopaedic Association, which includes four parts: upper limb motor function, lower limb motor function, sensory and bladder function, with a total score of 29 points. The lower the score, the more severe the neurological dysfunction.