Immune responses against group B Streptococcus monovalent and pentavalent capsular polysaccharide tetanus toxoid conjugate vaccines in Balb/c mice.

Immunization of pregnant women with Group B Streptococcus (GBS) capsular polysaccharide (CPS) conjugate vaccine (CV) could protect young infants against invasive GBS disease. We evaluated the immunogenicity of investigational five GBS monovalent (serotypes Ia, Ib, II, III, and V) CPS-tetanus toxoid (TT)-CV with adjuvant and GBS pentavalent CPS-TT-CV with adjuvant (GBS5-CV-adj) and without adjuvant (GBS5-CV-no-adj), in Balb/c mice. Aluminum phosphate was the adjuvant in the formulations, where included. The homotypic immunoglobulin G (IgG) geometric mean concentration (GMC) and opsonophagocytic activity (OPA) geometric mean titer (GMT) did not differ after the third dose of the GBS5-CV-adj vaccine compared with the monovalent counterparts for all five serotypes. The GBS5-CV-adj induced higher post-vaccination serotype-specific IgG GMCs and OPA GMTs compared to GBS5-CV-no_adj. The GBS5-CV with and without adjuvant should be considered for further development as a potential vaccine for pregnant women to protect their infants against invasive GBS disease.

Motives for deliberate self-harm in a South African tertiary hospital.

BACKGROUND: Although there is a growing body of literature on the epidemiology of deliberate self-harm (DSH) in South Africa, comparatively few studies have investigated the motives for self-harm. No studies have investigated the motives for DSH in Cape Town. AIM: The objective of the study was to identify the range of motives for DSH in Cape Town, and how these motives are associated with different socio-demographic factors, the severity of self-injury and levels of suicidal intent. SETTING: Groote Schuur Hospital in Cape Town, South Africa. METHODS: Data were collected from 238 consecutive patients presenting with DSH to the emergency department. The data were analysed by using bivariate and multivariate analyses. RESULTS: Patients engaged in DSH for a range of motives. Interpersonal issues were the most common motive (70%), followed by financial concerns (22%). Male patients were twice as likely as female patients to report interpersonal motives for their self-harm. Patients who reported interpersonal issues were more likely to engage in methods of DSH that involved damage to body tissues. Patients without tertiary education were more likely to report academic concerns as a motive, and patients who reported psychiatric illness as motive for DSH were more likely to require medical interventions than those who did not. CONCLUSION: This study contributes novel insights into the motives for DSH in the Cape Town context and provides the foundation for continued research on the subject. The study also gives impetus to the development of therapeutic interventions focussed on the motives for self-harm.

Enrichment of maize and triticale bran with recombinant Aspergillus tubingensis ferulic acid esterase.

Ferulic acid is a natural antioxidant found in various plants and serves as a precursor for various fine chemicals, including the flavouring agent vanillin. However, expensive extraction methods have limited the commercial application of ferulic acid, in particular for the enrichment of food substrates. A recombinant Aspergillus tubingensis ferulic acid esterase Type A (FAEA) was expressed in Aspergillus niger D15#26 and purified with anion-exchange chromatography (3487 U/mg, Km  = 0.43 mM, Kcat = 0.48/min on methyl ferulate). The 36-kDa AtFAEA protein showed maximum ferulic acid esterase activity at 50 °C and pH 6, suggesting potential application in industrial processes. A crude AtFAEA preparation extracted 26.56 and 8.86 mg/g ferulic acid from maize bran and triticale bran, respectively, and also significantly increased the levels of p-coumaric and caffeic acid from triticale bran. The cost-effective production of AtFAEA could therefore allow for the enrichment of brans generally used as food and fodder, or for the production of fine chemicals (such as ferulic and p-coumaric acid) from plant substrates. The potential for larger-scale production of AtFAEA was demonstrated with the A. niger D15[AtfaeA] strain yielding a higher enzyme activity (185.14 vs. 83.48 U/ml) and volumetric productivity (3.86 vs. 1.74 U/ml/h) in fed-batch than batch fermentation.

Protein production in Yarrowia lipolytica via fusion to the secreted lipase Lip2p.

We established a strategy for protein production and purification via expression in Yarrowia lipolytica as Lip2p fusion protein. To evaluate the expression system a cysteine-rich miniprotein, an antibody fragment and an enzyme showing galactose oxidase activity were chosen. These proteins have varying disulfide bond content, size, and structural complexity. Endogenous lipase Lip2p was used as a fusion partner to direct the fused proteins to the extracellular medium. A linker sequence was introduced at the junction of Lip2p and the respective fused protein that contains a hexahistidine tag followed by a TEV protease cleavage site. This allows for a specific and simple purification via IMAC for capturing the secreted proteins from the supernatant followed by a second IMAC for removing all contaminants after proteolytic release of the protein of interest. Up to 174 mg/L fusion protein was obtained using shake flask cultivation. Functionality of each of the purified proteins was confirmed by individual assays. Expression of proteins of interest via Lip2p fusion not only provides a convenient expression and purification scheme but also enables for an online monitoring of accumulation of secreted fusion proteins in the medium by exploiting the intrinsic lipase activity of the fusion.

Heterologous expression and optimized production of an Aspergillus aculeatus endo-1,4-beta-mannanase in Yarrowia lipolytica.

The Aspergillus aculeatus MRC11624 man1 gene, encoding an endo-beta-1,4-mannanase, was cloned and expressed in the promising heterologous enzyme producer, the ascomycetous yeast Yarrowia lipolytica. Both single- and multi-copy transformants were constructed, and the secretion of the enzyme was evaluated as an in-frame fusion with the LIP2 secretion signal, as well as with its natural secretion signal. In shake-flask analysis, the highest volumetric enzyme activity (13,073 nkat/ml) and specific enzyme activity (1,020 nkat/(mg dcw)) were obtained with a multi-copy integrant utilizing beta-mannanase's own secretion signal. The best beta-mannanase-producing strain was subsequently evaluated in batch fermentation and resulted in a maximum volumetric enzyme activity of 6,719 nkat/ml. Fed batch fermentations resulted in a 3.9-fold increase in volumetric enzyme activity compared with batch fermentation, and a maximum titre of 26,139 nkat/ml was obtained. The results reported in this study indicate that Y. lipolytica is a promising producer of A. aculeatus beta-mannanase, producing higher beta-mannanase activity than that of recombinant Saccharomyces cerevisiae or Aspergillus niger when cultivated in shake flasks, which is encouraging for the use of the enzyme in industrial processes such as extraction of vegetable oil from leguminous seeds and the reduction in viscosity of coffee extracts.

Production of the Aspergillus aculeatus endo-1,4-beta-mannanase in A. niger.

The beta-mannanase gene (man1) from Aspergillus aculeatus MRC11624 (Izuka) was patented for application in the coffee industry. For production of the enzyme, the gene was originally cloned and expressed in Saccharomyces cerevisiae. However the level of production was found to be economically unfeasible. Here we report a 13-fold increase in enzyme production through the successful expression of beta-mannanase of Aspergillus aculeatus MRC11624 in Aspergillus niger under control of the A. niger glyceraldehyde-3-phosphate dehydrogenase promoter (gpd (P)) and the A. awamori glucoamylase terminator (glaA(T)). The effect of medium composition on mannanase production was evaluated, and it was found that the glucose concentration and the organic nitrogen source had an effect on both the volumetric enzyme activity and the specific enzyme activity. The highest mannanase activity levels of 16,596 nkat ml(-1) and 574 nkat mg(-1) dcw were obtained for A. niger D15[man1] when cultivated in a process-viable medium containing corn steep liquor as the organic nitrogen source and high glucose concentrations.