Application Of Metagenomic Sequencing Technology In The Detection Of Pathogens Of Central Nervous System Infectious

Objective Central nervous system infection is a very dangerous and critical illness with a high mortality rate.In order to improve the prognosis of patients,it has become clinically consensus to take medication as soon as possible after suspecting that the patient is a central nervous system infection.This has caused many cases to be treated before lumbar puncture.Traditional pathogenic tests such as culture and staining microscopy have significantly reduced the detection rate of pathogens after treatment.Molecular biology methods have brought new light to the detection of pathogens of infectious diseases.At present,various molecular biological methods based on PCR such as real-PCR,multi-channel PCR,16 S PCR,and second-generation sequencing of metagenomics are used in infectious diseases,and the field of pathogen detection is booming.This study intends to perform next-generation sequencing of cerebrospinal fluid in cases with traditional etiology and clinical diagnosis of CNS infections to analyze the types of pathogenic microorganisms in CNS infections.Method The clinical cerebrospinal fluid samples used in the study were from specimens of suspected cases of central nervo us system infection submitted by the Department of Neurology and Cerebrospinal Fluid Room of the hospital where the specimens were stored between January 2017 and January 2019.We performed next-generation sequencing on a total of 542 patients suspected of having a central nervous system infection.The inclusion criteria are as follows: suspected patients with clinical manifestations such as headache,fever,neck stiffness,and altered consciousness;or patients with central nervous system infection with atypical clinical manifestations,but cerebrospinal fluid biochemistry,cytology abnormalities,and infection cannot be excluded.The sequencing platform is an Illumina Miniseq sequencer.During the experiment,sterile water was strictly set as a negative control,and plasmid DNA of a known concentration was used as a positive quality control.The same batch of sequencing results were compared between samples to determine whether the experiment was contaminated.NGS positive results are interpreted according to internationally recognized standards and the actual conditions of this laboratory.After the samples were collected,the case information was collected,and the relationship between the second-generation sequencing results and the clinic was analyzed.Results This study collected clinical information of 542 patients with suspected central nervous system infection.Of the 542 specimens,145(27%)were positive for traditional etiological tests,and 294(54%)were NGS-positive specimens.The overall detection rate was The detection rate of traditional pathogens has doubled(27%).Among them,the cases of bacterial meningitis,tuberculous meningitis,viral meningitis,fungal meningitis,and parasitic meningitis were 160,100,241,25,and 7,respectively,and the confirmed cases of pathogens were 24(15%),65(65%),18(7%),22(88%),7(100%),the second-generation sequencing positive samples of metagenomics were 102(62%),76(76%),79(32%)),23(92%),7(100%).Metagenome second-generation sequencing has also discovered a large number of opportunistic pathogens and mixed infections in addition to common pathogenic pathogens.Conclusion Our research found that second-generation sequencing technology can improve the detection rate of pathogens,and has advantages in identifying rare or difficult-to-cultivate pathogens,and is very helpful for differential diagnosis,such as helping to identify tuberculous meningitis,brucellosis,Cryptococcal meningitis and so on.