The Use of Genome Sequencing in the Study of the Etiology of Postoperative Meningitis in Patients in the Neurosurgical ICU

Objectives. The study of bacterial DNA in the CSF samples from patients with clinical signs of meningitis but with negative results of cultural and PCR methods. Materials and Methods. The study included 3 patients from neuro-ICU. All patients had clinical signs of post-neurosurgical meningitis. The DNA was extracted from CSF samples obtained from those patients; then PCR with universal bacterial primers (27F & 1492R specified to 16S rRNA genes) was performed. PCR product was cloned into DNA vector, and the library of 16S rRNA genes fragments was created in E.coli K12 strain. 16S rRNA gene fragments from random colonies were sequenced by Sanger method. Obtained sequences were identified using BLAST and SILVA databases. We investigated 21 clones from the library in total. Results. Bacterial DNA was found in CSF samples from all patients included in the study. The most frequent species was Propionibacterium spp. (7 out of 21 clones), Enterobacter spp., and other Gram-negative bacteria (6 out of 21 clones); Staphylococcus and other Gram-negatives were found in 5 out of 21 clones. We also found atypical species like Psychrobacter spp., which can cause meningitis. Conclusions. These results provide the basis to suggest that in some cases of post-neurosurgical meningitis, which used to be considered as aseptic, CSF does contain bacteria. Etiological role of those bacteria remains unclear further research is required