Causative agents of bacterial meningitis

Central nervous system infections include several clinical involvements with a wide clinical distribution and variable course and outcome. One of the most frequently encountered infections is bacterial meningitis which may lead to serious consequences with respect to development of complications. This  study has been conducted with the aim to investigate the causative agents of bacterial meningitis. One hundred patients with a clinical prediagnosis of meningitis were enrolled in the study. Their cerebrospinal fluid samples were obtained for biochemical examination, cell count, Gram staining and giemsa staining. Samples were cultured for bacteriological examination. Conventional methods and Vitek2 were used for identification. Molecular evaluation of the samples was carried out with multiplex PCR based on hybridization. For this purpose, Speed-Oligo Bacterial Meningitis kit was used and Haemophilus influenza, Neisseria meningitidis and Streptococcus pneumoniae were explored. A total of 34 samples were shown to have bacterial infection; a bacterial agent was isolated by culture from each of 25 CSF samples of all 100 tested samples. Most frequently isolated microorganisms were Staphylococcus epidermidis (4 samples, 16%), Corynebacterium spp. (4 samples, 16%) and S. pneumoniae (2 samples, 8%). Only 15 samples were positive with PCR, in 10 of the samples (10%). S. pneumoniae was detected and H. influenzae was detected in 5 of them (5%) while N. meningitidis was not found in any of the samples. Only one sample showed yeast infection. Aseptic viral infection was evident based on leukocyte, glucose, and protein vales, but was not demonstrated by specific tests.   Key words: Bacterial meningitis, Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis.