Pathogenic Bacteria High-throughput Sequencing And Species Analysis In Cerebrospinal Fluid With Purulent Meningitis

Objective Research in common types of bacteria，abundance of bacterial andstructure of community microbial in the cerebrospinal fluid of patients with purulentmeningitis pathogens，and to explore a new way of the etiological diagnosis with purulentmeningitis.Methods Select61cerebrospinal fluid samples of the clinical diagnosis purulentmeningitis patients in this study. Extract bacterial genomic DNA of the purulent meningitispatients in CSF and then identified by PCR. Culture the bacterial of CSF. Calculate thepositive rate of these two methods，and compared with the two positive rate by the chi-squaretest with spss17.0statistical software. Use high-throughput sequencing for the PCR-positivesamples by16S rDNA metagenomic sequencing technology，and then integrate and analysisthe sequencing results by bioinformatics analysis method.Conclusions Culture and test bacterial for61CSF samples with purulentmeningitis patients，there are26specimens amplified specific DNA product at550bp，andbacterial culture specimens are only10cases. The positive rate of16S rDNA PCR is42.6%.The positive rate of bacterial culture is16.4%. The results of16S rDNA metagenomicsequencing technology and bioinformatics techniques: CSF containing the species isrelatively less than other environment by the observing the OTU number of each sample. Thetype of bacteria can be roughly divided into Firmicutes and Proteus at the phylum in thepurulent meningitis CSF samples. The main species of bacteria are Streptococcus,Acinetobacter, Pseudomonas and Neisseria at the genus. Analysis by beta diversity, the bacterial species of purulent meningitis CSF are little differences between any two sample inthe genus level.Results Diagnosis of purulent meningitis positive rate of the two detectionmethods, PCR method is better than isolation and culture method (P <0.05); This studyselected DNA extraction method by QIAGEN DNeasy Blood and Tissue Kit，primers andPCR conditions were better，good amplification of16S rDNA of the CSF with purulentmeningitis. And obtained genomic DNA can be applied to the metagenomics subsequent dataanalysis and research. Though analysis the type，the abundance and the structure of bacteriawith CSF of purulent meningitis patients by16S rDNA metagenomic sequencing technologyin Yinchuan，the dominant flora is Streptococcus，Acinetobacter and Pseudomonas，and someunknown bacteria is also a major factor to cause intracranial infection.