Search

Accurate and timely diagnosis of acute bacterial meningitis is critical for antimicrobial treatment of patients. Although PCR-based methods have been widely used for the diagnosis of acute meningitis caused by bacterial pathogens, the main disadvantage of these methods is their high cost. This disadvantage has hampered the widespread use of molecular assays in many developing countries. The application of multiplex assays and "in-house" protocols are two main approaches that can reduce the overall cost of a molecular test. In the present study, an internally controlled tetraplex-PCR was developed and validated for the specific detection of Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae in cerebrospinal fluid (CSF) samples. The analysis of a panel of other human pathogens showed no cross-reactivity in the assay. The analytical sensitivity of the in-house assay was 792.3 copies/ml, when all three bacteria were presentin the specimens. This value was calculated as 444.5, 283.7, 127.8 copies/ml when only S. pneumoniae, N. meningitidis and H. influenzae, respectively, were present. To demonstrate the diagnostic performance of the assay, a total of 150 archival CSF samples were tested and compared with a commercial multiplex real-time PCR kit. A diagnostic sensitivity of 92.8% and a specificity of 95.1% were determined for the present tetraplex-PCR assay. The results indicate that the established method is sensitive, specific and cost-effective, and can be used particularly in situations where the high cost of commercial kits prevents the use of molecular methods for the diagnosis of bacterial meningitis.

Background Cell-mediated immunity including T-cells (T helper and cytotoxic) plays an essential role in efficient antiviral responses against coronavirus disease-2019 (COVID-19). Therefore, in this study, we evaluated the ratio and expression of CD4 and CD8 markers in COVID-19 patients to clarify the immune characterizations of CD4 and CD8 T-cells in COVID-19 patients. Methods Peripheral blood samples of 25 COVID-19 patients and 25 normal individuals with similar age and sex as the control group were collected. White blood cells, platelets, and lymphocytes were counted and CD4 and CD8 T lymphocytes were evaluated by flow cytometry. Results The number of white blood cells, lymphocytes, and platelets were reduced significantly in COVID-19 patients (P 0.05); however, the CD8 MFI increased significantly in COVID-19 infected patients (P