Bacillus dicomae sp. nov., a new member of the Bacillus cereus group isolated from medicinal plant Dicoma anomala.

A Gram-stain-positive, endospore-forming endophytic bacterial strain designated MHSD28T was isolated from surface-sterilized leaves of Dicoma anomala collected from Eisleben, Botlokwa, Limpopo Province, South Africa. The phenotypic and phylogenetic characteristics of strain MHSD28T were consistent with those of members within the Bacillus cereus group. Comparative analysis between this strain and its relatives confirmed that it belongs to this group and forms a monophyletic branch. The digital DNA-DNA hybridization values between strain MHSD28T and its relatives were lower than the 70 % threshold for species delineation. To further determine its phylogenetic position, multi-locus sequence analysis (MLSA) based on five concatenated housekeeping gene (gyrB, atpD, DnaK, rpoB and rpoD) sequences, phenotypic analysis, matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) biotyper identification, fatty acid and polar lipid profile analyses were carried out. Phenotypic characterization, MLSA, whole genome sequence based analyses and MALDI-TOF results placed strain MHSD28T within the B. cereus group. The major fatty acids were iso-C15 : 0 and summed feature 3 and the main polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The respiratory quinone was menaquinone-7. The cell-wall peptidoglycan structure included meso-diaminopimelic acid. Considering the above results, strain MHSD28T represents a novel species of the B. cereus group, for which the name Bacillus dicomae sp. nov. is proposed. The type strain is MHSD28T (=BD 2262T=LMG 32287T=CECT 30671T).

Apoptotic potential role of Agave palmeri and Tulbaghia violacea extracts in cervical cancer cells.

Cervical cancer, a gynaecological malignant disorder, is a common cause of death in females in Sub-Saharan Africa, striking nearly half a million of lives each year worldwide. Currently, more than 50 % of all modern drugs in clinical use are of natural products, many of which have an ability to control cancer cells (Madhuri and Pandey, Curr Sci 96:779-783, 2009; Richter, Traditional medicines and traditional healers in South Africa, 2003). In South Africa, plants used to treat cancer are rare even though majority of our population continue to put their trust in traditional medicine. In this study we aimed to screen Agave palmeri (AG) and Tulbaghia violacea (TV) for potential role in inducing cell death in cervical cancer cell lines HeLa and ME-180, and in normal human fibroblast cell line KMST-6 cell lines. To achieve this, AG and TV crude extracts were utilized to screen for apoptosis induction, inhibition of cell proliferation followed by elucidation of the role of Bax, Bcl-2, p53, Rb, RBBP and Mdm2 genes in cervical cancer. In brief, plant leaves and roots were collected, crushed and methanolic extracts obtained. Different concentrations of the stock extracts were used to treat cancer cells and measure cell death using the [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay and flow cytometry. Western blot was applied to measure gene expression at protein level using RBBP6, p53, Mdm2, Rb, Bax, Bcl-2 and ß-actin mouse monoclonal primary antibodies (IgG) and goat anti mouse coupled with horseradish peroxidase secondary antibody from Santa Cruz Biotechnology and real time-PCR was used for mRNA expression level. Plant extracts of AG and TV were time (24 h) and dose (50, 100, 150 µg/ml) dependent in their induction of cell death with an IC50 ~ 150 µg/ml. A further mixed respond by several genes was observed following treatment with the two plant extracts where RBBP6 was seen to be spliced in cancer cells while Bax was induced and Bcl-2 was inhibited with the levels of p53 remaining the same. The two plant extracts do induce cell death, in a p53 independent manner.