Subset of patients whose CSF samples were analyzed in this study.

A first CSF sample was collected during the previous surgery and a second during the subsequent infection episode. Column “Days” shows the time interval between previous surgery and infection samples. Results from standard clinical microbiology culture are shown. Exceptions are indicated when the date of the culture sample differed from the date of the sample used in this study. 5 patients are not shown in this table, who were not tested by microbiology culture at the previous surgery and/or had polymicrobial results during the infection episode. The full list of patients is available in S1 Table.