Rapid Diagnosis of Bacterial Meningitis Using a Microarray

Abstract

Microarrays, or biochips, are a new technology that can allow rapid detection of bacterial genetic materials. To explore their practical applications, we compared use of a microarray for the diagnosis of bacterial meningitis with the traditional blood and cerebrospinal fluid (CSF) culture methods. Samples from 50 patients with suspected bacterial meningitis were analyzed by microarray and by traditional blood and CSF cultures. Among all samples, 11 were positive by microarray analysis, seven were positive by CSF bacterial culture and six were positive by blood culture. CSF pleocytosis was found in 26 patients. Of these, eight were positive by microarray analysis, seven were positive by CSF culture and five were positive by blood culture. The percentage of positive results from microarray analysis was 22%, compared to 14% by CSF culture and 12% by blood culture. The CSF bacterial culture method had the highest positive predictive value and specificity (both 100%). The sensitivity of microarray analysis was higher (30.8%) than that of CSF and blood cultures (26.9% and 19.2%). All three methods had a similar negative predictive value in the range of 52.3-55.8%. Of the 11 microarray positive samples, four were identified successfully in CSF culture (36.4%) and three samples were identified in blood culture (27.2%). One of the microarray positive samples was diagnosed as a polymicrobial infection (9%), and the rest were monomicrobial infections. The microarray method provides a more accurate and rapid diagnostic tool for bacterial meningitis compared to traditional culture methods. Clinical application of this new technique may reduce the potential risk of delay in treatment.