Development and Assessment of a Diagnostic DNA Oligonucleotide Microarray for Detection and Typing of Meningitis-Associated Bacterial Species.

Meningitis is commonly caused by infection with a variety of bacterial or viral pathogens. Acute bacterial meningitis (ABM) can cause severe disease, which can progress rapidly to a critical life-threatening condition. Rapid diagnosis of ABM is critical, as this is most commonly associated with severe sequelae with associated high mortality and morbidity rates compared to viral meningitis, which is less severe and self-limiting. We have designed a microarray for detection and diagnosis of ABM. This has been validated using randomly amplified DNA targets (RADT), comparing buffers with or without formamide, in glass slide format or on the Alere ArrayTubeTM (Alere Technologies GmbH) microarray platform. Pathogen-specific signals were observed using purified bacterial nucleic acids and to a lesser extent using patient cerebral spinal fluid (CSF) samples, with some technical issues observed using RADT and glass slides. Repurposing the array onto the Alere ArrayTubeTM platform and using a targeted amplification system increased specific and reduced nonspecific hybridization signals using both pathogen nucleic and patient CSF DNA targets, better revealing pathogen-specific signals although sensitivity was still reduced in the latter. This diagnostic microarray is useful as a laboratory diagnostic tool for species and strain designation for ABM, rather than for primary diagnosis.

Evaluation of cytotoxic activity of protein extracts from the leaves of Morinda pubescens on human cancer cell lines

ABSTRACT Biologically active proteins isolated from plant species can be used in traditional medicine as prolific resources for new drugs Morinda pubescens Sm., Rubiaceae, is a promising medicinal plant which is widely used in folk medicine to treat fever due to primary complex, ulcer and glandular swellings. In this study, proteins were extracted from the leaves of M. pubescens, and precipitated with ammonium sulphate at various saturation concentrations ranging from 20 to 80%. The precipitated protein sample obtained with 80% saturation was further purified using ultrafiltration membrane (<10 kDa). SDS-PAGE analysis identified the presence of crude and ultrafiltered protein bands. FTIR spectrum of the ultrafiltered protein fractions depicted the presence of hydroxyl and carbonyl groups of proteins. The ultrafiltered proteins exhibited increased cytotoxic activity on A549 cells at the concentrations ranging from 15 to 100 µg/ml. About 98% cell viability was also observed in Vero cells treated with the maximum concentration of 100 µg/ml of ultrafiltered protein extract. DNA fragmentation was observed in A549 cells treated with 10 µg/ml of ultrafiltered proteins, indicating the onset of apoptosis.